KR20000005548A - Cutting tool for eliminating chip and connecting pin - Google Patents

Abstract

PURPOSE: A cutting tool having a connecting pin is provided to set up the position of a cutting insertion body having a straight cylindrical hole and a cutting insertion body having a profile hole. CONSTITUTION: The cutting tool(10) for eliminating a chip is formed by:a tool(10) provided to be indirectly connected by passing through a core(13) in opposition to a holder(11) and a base surface(14); a cutting insertion body(12A) having a penetrating slot provided to be connected in opposition to a supporting surface(15, 16) of a pocket of the cutting insertion body in the holder(11); a quick acting connecting pin(18) inserted into a bore(17) of the holder(11), accepted by an insertion body hole(19A), made up of a head(20), a waist(21), a first cone unit(22) and a screw unit(23), and having a common central shaft(CL1) in a no-load state.

Description

Chip removal cutting tools and fastening pins

U. S. Patent No. 3,341, 920 discloses a cutting tool of the type described above. The cutting tool consists of a negative cutting insert with a cylindrical insertion hole. The fastening pin is configured to be inclined upon tightening so that the cutting insert is pressed toward the supporting surface in the holder. However, these support surfaces may be provided at nearly 90 ° relative to the base surface of the insert pocket to engage the cutting insert in the correct position. In this case, so-called positive cutting inserts must be positioned and other types of fastening pins are required. Such a pin is disclosed, for example, in U.S. Patent No. 3,341,923, wherein the fastening pin consists of a conical head such that the cutting insert is pressed against a support surface that is obtuse with the base surface and simultaneously the cutting insert is opposed to the base surface. Press down.

US 4,869,624 discloses a cutting tool having a detachable cutting insert secured by an elastically curved fastening screw. The fastening screw must be removed completely when another cutting insert must be mounted.

The present invention relates to a chip removal tool comprising a cutting insert having a holder and a through hole and provided to abut against a support surface and a base surface in an insertion pocket of the holder, the holder receiving threaded fastening pins protruding into the insertion holes. A bore, the pin comprising a head, a waist, a cone and a thread, the pins being configured for quick actuation, and the portions of these pins having a common central axis under no load conditions. Consists of a conical recess provided to displace the cutting insert in the direction towards the support surface by the pin when tightening the pin on the threaded portion of the bore.

These and other objects are achieved by cutting tools and fastening pins according to the invention as defined in the appended claims with reference to the drawings.

1 is a perspective view of a fastening pin according to the present invention.

2A and 2B are partial side cross-sectional views illustrating a cutting tool according to the present invention.

3 is a partial side cross-sectional view showing a cutting tool according to another embodiment of the present invention.

4 is a plan view of the cutting tool.

5A, 5B and 5C are partial side cross-sectional views illustrating a mounting process of the cutting tool according to FIGS. 2A and 2B.

6A and 6B are partial side cross-sectional views illustrating the mounting process of the cutting tool generally in accordance with FIG.

7 shows a possible final position of the mounting according to FIGS. 6A and 6B.

8 is a cross-sectional view of a cutting insert with a double profile hole.

It is an object of the present invention to provide a cutting tool with a quick acting fastening pin on which a cutting insert with a straight cylindrical hole and a cutting insert with a profile hole can be positioned.

It is another object of the present invention to provide a cutting tool with quick acting fastening pins in which the cutting insert can be quickly positioned in a safe manner.

The chip removing cutting tool according to the present invention is indicated by reference numeral 10 in FIGS. 2A and 2B. The tool 10 is provided so as to be in direct contact with the holder 11 and the base surface 14 directly or indirectly via the shim 13 and support surface 15 of the cutting insert pocket in the holder 11. , A cutting insert 12A having a through hole provided to abut against 16. The quick acting fastening pin 18 fitted into the bore 17 of the holder is received by the insert hole 19A.

Stated another way, the cutting tool is preferably perpendicularly through the base pocket and the insert pocket comprising a base surface 14 and support surfaces 15, 16 extending upwardly from the base surface 14. A holder 11 having a bore 17 extending downward and a main surface seated in the pocket and engaging with the base surface 14, a side surface supported by the support surface and a major surface with at least one cutting edge. A cutting insert 12 that is constructed, a through hole extending through the insert from one main surface to the other main surface, and insertable through the through hole and detachably attaching the insert to the holder, Shovel through the through hole to allow the insert to be detached from and seated on the pocket without completely separating the pin from the through hole. Available and consists of a retaining pin 18, the fixing can screwed into the through-hole.

The pin 18 is comprised from the head 20, the waist 21, the 1st cone part 22, and the threaded part 23, as apparent from FIG. 1, FIG. 2A, and FIG. 2B. Portions of these pins have a common central axis CL1 in the no-load state. The head 20 is generally slightly conical and connects to the second cone 24 by a radius R1. The second cone 24 is defined by an acute angle α which lies at an interval of 40 ° to 70 ° and is preferably at an angle of about 60 °. The other side of the cone 24 continues to be connected to the waist 21 by the radius R2. Radius R2 is larger than radius R1 and is 0.2 mm in size. Radius R1 is chosen small to maximize the cover surface of the head, but radius R2 is chosen larger than R1 for reasons of strength. The waste 21 slightly increases the cross-sectional area in the direction towards the radially projecting flange 25 provided to safely protect the shim 13 against unintended no load in a known manner. The transition between the waist and the flange is caused by a recess in which the radius R3 extends beyond the radius R2 at least to the element 4 because a relatively large stress in use affects this region of the pin. Is formed. The flange continues to connect to a cylindrical portion 26 that connects to the first cone portion 22. The first cone portion 22 is defined by an acute angle β, which is placed at intervals of 40 ° to 70 ° and is preferably at an angle of 60 °, in order to quickly tilt the pin during insert mounting. The first cone portion is connected to the threaded portion 23 via the second waist 27. The threaded portion 23 is partially spherical to allow tilting despite engagement with the screw bore 17. Key grips are provided on the upper and lower free end faces of the pin. The total length of the pin is indicated by L, with about 8-12%, preferably about 10% of the total length of the pin making up the height h of the head 20 and about 4% of the cone 24. The length w of the waist 21 toward the flange 25 constitutes an axial dimension (c) while the length w constitutes 24 to 32% of the length L, preferably about 28%. The dimensions L, h, c and w are measured in parallel with the central axis CL1.

In the holder 11, the bore 17 consists of a conical recess 28 provided to displace the cutting insert in the direction toward the support surface by the pin when tightening the pin to the threaded portion 17 of the bore. The recess 28 has a centerline CL2 displaced in a known manner to form a defined one side contact surface 28 suitable for the conical surface 22 of the pin. The contact surface 28 faces the support surfaces 15, 16. The recesses 28 are defined by an acute angle ε which is placed at intervals of 40 ° to 70 ° and preferably at an angle of 60 ° to obtain a contact as close to the base surface 14 as possible. The angle [epsilon] must consequently be greater than the angle [beta].

Shim 13 is polygonal and has the same basic shape as the associated cutting insert and has a center hole for receiving pin 18. The hole consists of a shoulder provided to cooperate with the flange 25 on the pin. The smallest diameter of the shoulder is smaller than the largest diameter of the flange 25 so that the shim does not loosen from the holder, for example during insert change. The cutting insert 12A has a negative basic shape in the embodiment according to FIGS. 2A and 2B. This means that the major face of the cutting insert is perpendicular to its side. The cutting insert generally has a cylindrical hole 19A.

In Fig. 3, a cutting insert having a positive basic shape is shown, wherein the upper major surface of the cutting insert forms an acute angle with its sides. The hole 19B of the cutting insert is shaped and consists of a cylindrical lower portion 30, a cone portion 31 and a radially larger cylinder portion 32. The cone part 31 is spaced at an interval of 40 ° to 70 ° and is preferably defined by an angle of 60 °, that is, an acute angle as large as the above-described angles α and β. This type of profile hole may also be used in the negative insert shape and the hole 19C of the cutting insert 12C may be a double profile as shown in FIG. Since the cutting insert is placed on the support surfaces 15 and 16 at the time of fastening, a pure cylindrical hole cannot be used as a positive insert shape when assembling with the fastening pin of the present form.

When mounting the negative cutting insert in the holder according to Figs. 2A, 2B, and 5A to 5C, the cutting insert 12A has a hole 19A in which the main part of the head 2 and the waist 21 of the pin are mounted. Bring over pin to occupy. It is to be understood that in this state the shim 13 is mounted in a known manner and the cooperative teeth are completely engaged with each other and the central axis CL1 of the pin is generally coincident with the central axis CL of the bore 17. Subsequently, the pin is rotated via the key grip with some suitable tool such that the conical surfaces 22, 28 abut against each other. The pin is inclined during subsequent screwing such that the cylindrical cover surface of the head 20 abuts against the cylindrical bore wall of the cutting insert according to FIG. 5B. Thereby, the cutting insert is displaced until its sides engage with the respective support surfaces 15, 16. In order to compensate for the maximum 1 ° angle change at which the pin is inclined, as well as the elastic deformation accompanying the support surface and the plastic deformation accompanying the pin, the head has an angle of about 1 to 2 ° with respect to the central axis CL1. And conical shape with vertices facing away from base surface 14 to prevent lifting of the front edge of the cutting insert. Thereby, the line or zone of the contact is obtained between the head and the hole instead of just the point of contact at the radius R1 as shown in FIG. The positions according to Figures 5A and 5C are separated by about three quarters of turns upon the rotation of the pin so that the last eighth round forms a line or zone of the contact according to Figure 5C.

When the cutting insert is mounted according to Figs. 3, 6A and 6B, the cutting insert 12B / 12C is placed above the pin in the manner described above so that the holes 19B / 19C occupy the main part of the head and waste of the pin. Done. Continuously, the pins are rotated such that the conical surfaces 22, 28 abut against each other. Further tightening the screw, the pin is tilted with an overall angle change of about 3 ° to allow the other cone 24 to engage the cone 31 of the holes 19B / 19c. Thereby, the cutting insert is displaced until its sides engage with the support surface configured for the actual insert shape. In addition, further tightening the screw inwards causes the pin to be elastically prestressed while the position of the cutting insert is no longer changed, as shown in FIGS. 3 and 6B. In this position, the cutting insert is supported in a safe manner.

Alternatively, the tolerance of the participating component may be configured such that the waste 21 abuts against the insert hole as shown in FIG. According to this, two positions of the contact are generated between the pin and the insert hole to provide a continuous tightening force on the cutting insert. Since the waste is slightly conical, about 3 ° in the direction towards the head, the cover surface of the waste 21 abuts along the line portion facing the cylindrical bore wall 30 in the cutting insert. The latter indicates that the user experiences a sudden increase in the torsional resistance of the pin and that the pin is tight enough. In the position according to Fig. 7, the pin is about three quarters rounded so that the last eighth round forms the line contact.

The basic concept of the present invention is that the fastening pin is configured in a quick acting manner without removing the cutting insert 10 so that the fastening pin 18 can be mounted / detached from the holder body. In fact, limited axial displacement of the fastening pins is required to allow the cutting insert 12 to be mounted / detached. Accordingly, the pin 18 is a cutting insert having a straight cylindrical hole and a cutting insert having a profile hole by bending the head 20 and the waist 21 while tightening the pin in a direction away from the supporting surfaces 15 and 16. It is possible to fasten both so that the displacement portion 24 between the head and the waist cooperates with the cone portion 31 of the insert holes 19A, 19C, while only the head cooperates with the cylindrical insert hole. This means that it is possible for a user to use many different cutting features in one holder.

Claims (10)

And a cutting insert (12A, 12B, 12C) having a holder (11) and a through hole and provided to abut against the support surface (15, 16) and the base surface (14) in the insert pocket of the holder. The holder has a bore 17 for receiving a fastening pin with a screw formed to protrude into the hole of the insert, which pin is composed of a head 20, a waist 21, a cone 22 and a thread 23 The part of the pin has a common central axis in the no-load state, the pin is configured for quick actuation, and the bore 17 cuts in the direction toward the support surface via the pin when tightening the pin to the thread of the bore. A tool for chip removal comprising a conical recess 28 provided to displace the The pin 18 can fasten not only the cutting insert 12A having the straight cylindrical hole 19A but also the cutting inserts 12B, 12C having the profile holes 19B, 19C in the insert pocket. To elastically curve at least the head 20 at the last tightening stage of the pin in a direction away from the support surfaces 15, 16, At least one displacement portion 24 between the head and the waist cooperates with the profile holes 19B, 19C in the cutting inserts 12B, 12C of the first type and the head in the cutting insert 12A of the second type. Tool characterized in that it cooperates with the cylindrical insert hole (19A). 2. The device of claim 1, comprising two or three possible contact points isolated in the height direction, which contact points between the first contact point between the head 20 of the pin and the other type of cutting insert 12A, and the displacement portion ( 24) and a third contact point between the waste 21 and the first type cutting inserts 12B and 12C in addition to the second contact point or the second contact point between the cutting inserts 12B and 12C of the first type. The tool is characterized in that it is calculated in the direction towards the base surface (14). The cone according to claim 1 or 2, wherein the head is conical in order to obtain contact line and / or face contact at the first contact point when mounted, and the cone having a vertex directed away from the base face 14 has a central axis CL1. Tool defined by an acute angle [mu] of about 1 [deg.] To 2 [deg.]. 4. The first of claim 1, 2 or 3, wherein the pin 18 and the bore 17 of the holder 11 form a first acute angle β / 2 with the center line CL1 of the fastening pin. The first acute angle is 20 ° to 35 °, preferably about 30 ° and the second contact point forms an acute angle α / 2 similar to the centerline CL1 of the fastening pin. Featured tool. The head (20) according to any of the preceding claims, characterized in that the head (20) has an axial length extension (h) that lies at an interval of 8 to 12%, preferably about 10% of the total length L of the pin. Tool made. Pin according to any one of the preceding claims, wherein the pin (18) consists of a flange (25) provided to hold a shim provided with a hole (13), said shim comprising a base surface (14), said shim being a cutting insert and a holder. A tool, characterized in that provided between. In any one of the preceding claims, the displacement portion consists of a cone portion 24 and about 4% of the total length L of the pin is constituted by the axial extension c of the cone portion 24. A length (w) from the waist (21) to the flange (25) is about 24 to 32%, preferably 28%, of the length (L). The head 20, the waist 21, the conical displacement portion 22, and the threaded portion 23, the portion of the form according to claim 1 such that these portions have a common central axis CL1 in a no-load state In the fastening pins for cutting tools, The pin 18 is separated from each other in the height direction consisting of a first contact point in the head 20 of the pin and a second contact point in the displacement portion 24 in addition to these two contact points. Fastening pins comprising two or three possible contact points, said contact points being calculated in a direction towards the threaded portion (23). 9. The head (20) according to claim 8, characterized in that the head (20) has an axial extension (h) arranged in an interval of 8 to 12%, preferably about 10% of the total length (L) of the pin. Fastening pins. 10. The pin (18) according to claim 8 or 9, wherein the pin (18) consists of a flange (25) defining the largest diameter of the pin and the displacement portion consists of a conical portion (24) and about 4 of the total length (L) of the pin. % Is constituted by the shaft length extension c of the cone 24, while the length w from the waist 21 to the flange 25 is about 24 to 32% of the total length L of the pin, Fastening pins, characterized in that consisting of preferably 28%.