JPH0478401B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting tool, and particularly to a blade thereof.

Continuous disposal of chips generated during cutting operations is a problem that exists in all cutting operations. This problem becomes more problematic when using rotary cutting tools with multiple blades. This is because, in addition to the current problem of chips, there is also the problem of chips resulting from cutting by previous blades, if not properly disposed of when they occur. To aid in chip removal and to minimize chip damage to the workpiece, it is known in the art to position the blades so that each blade cuts only a portion of the total cutting width. be. Blades with different cutting widths are used for similar purposes.
These alternative methods make the width of the chips smaller than the width of the cut and facilitate the disposal of the chips.

The use of blades in a zigzag arrangement and blades of different widths reduces the efficiency of the cutting operation. The use of a distinctive blade minimizes chip damage when rotating the workpiece and helps solve chip disposal problems.
However, if the cutting tool uses an insert, such an insert, if featured, may have a greater clamping force than an insert without features due to the additional forces created when forming a wide chip. Requires. The problem of chip disposal is made even more difficult by the need to tighten the insert into the blade support to overcome the centrifugal forces created by the rotational motion. There are a number of clamping devices available for retaining inserts. The tightening device takes up space and reduces the number of inserts that can be placed around the disc. The tightening device also requires a fastener that limits the thickness of the disc. This becomes a problem when the cutting tool is used to cut a groove across the width, such as a saw.

It is therefore an object of the present invention to provide a new cutting tool which substantially reduces or overcomes the problems and disadvantages mentioned above.

According to the invention, the present invention comprises a disc-shaped support, a plurality of blades around the support, and means on the blades for narrowing chips generated during groove cutting of a workpiece. An improved cutting tool is provided. In order to maximize the number of blades on the blade support, a novel feature of the blade allows the chips to be wound in a tight compact coil so that they occupy a minimum amount of space around the cutting tool. Ru.

The blade body or insert is configured to form chips such that the width of the chips is smaller than the width of the cutting edge of the insert. This structure is usually a protrusion arranged on the cutting surface of the blade and forming a part thereof. Thereby, the chips immediately after being sheared by the straight cutting edge of the insert blade are shaped. By shaping the chips while they are most flexible, power consumption is minimized. The internal forces curl the chips into a tight spiral shape.

Another object of the present invention is to provide an insert blade for use in a stationary blade support as well as a rotating blade support.

The insert blade is characterized by a protrusion that is spaced from the cutting edge and extends in the longitudinal direction between both edges of the upper cutting surface of the insert blade to control the shape of chips.

A recess is formed between the insert blades of the blade support to receive the spiral chips. The starting point of the recess is to facilitate the disposal of chips during cutting operations.
In order to reduce the distortion caused by the internal force generated by press-fitting the insert blade into the seat of the insert blade support, and to install more insert blades around the blade support, a disc-shaped blade support is used. A slotted hole is provided.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The present invention relates to a cutting tool for cutting grooves or dividing materials. The cutting tool of the present invention has two parts, namely, a disposable insert blade 8 and a disk-shaped blade support 1 having a concave seat 3 into which the insert blade 8 is fitted. The insertion blade 8 is usually made of hard metal.

Although a replaceable bayonet blade is shown, the present invention also encompasses those with integral blades or permanently attached blades.

The blade support 1 is usually a relatively thin metal disk having a thickness smaller than the width of the kerf produced by the insert blade 8 . A hole 23 is provided in the center of the blade support 1 for attaching the blade support to a rotating shaft.
There is. Although not shown, this hole 23 includes
A keyway is provided for keying the blade support to the rotating shaft.

The insert seat 3 corresponds to the shape of the insert blade 8. Above the catch seat 3 is a recess 17 for receiving chips.
It is used to store chips as described below. The cross-sectional shape of the catch jaws 4a, 4b is shown as protruding in a V-shape in FIG. 2, and as being concave in a V-shape in FIG. Each seat 3 has a removal recess 6 at its inner end. The removal tool 15 consists of a lever 16 and a handle 14 and is used to insert the lever 16 into the recess 6 and push out the insert not held by the clasp from the blade support. The disk constituting the blade support has an elongated arcuate hole, for example, a seat 3 around the disk.
A groove 2 is formed located between and extending towards the central hole 23. The groove 2 acts to compensate for the difference between internal forces and deformations occurring in the cutter body during cutting operations. The grooves 2 also increase the elasticity of the disc and seat the insert better on the disc.

During cutting operations, a device is provided for locking the inserts in position and preventing them from being released in response to the centrifugal force of their movement. That is, due to the geometry of the insert and the seat, the insert is retained in the seat during use despite the large forces acting on the insert. This geometrical shape is such that the triangular prisms of the catch are polygonal holding surfaces 10a, 10b, 11a, 11b (second,
Figure 3) and corresponding restraint wedge-shaped surfaces 5a, 5
It forms a wedge shape with b, 7a, and 7b. The insertion blade is positioned in the seat 3 of the blade support by the insertion force.

A cutting force, a force for gripping the insert, and a centrifugal force resulting from the rotational movement of the rotary cutting tool act on the insert attached to the rotary blade support. Since the cutting action by a rotary cutting tool is intermittent, it is extremely important to securely hold the insert in its seat. The insert of this rotary cutting tool is not held by a clasp, but instead by a wedge force. When inserting the wedge-shaped insert into the blade support between the wedge-shaped catch jaws of the blade support, a force is applied perpendicularly to the catch jaws. These vertical forces create a frictional force that retains the insert within the seat.

As the wedge angle α (Fig. 1) becomes smaller,
It is well known that for the same insertion force, the normal force increases and the frictional holding force increases. Therefore, when the wedge angle α is reduced, a stronger wedge force acts on the insert blade in the strike plate,
The reliability of holding the insert is increased. However, the reduction in wedge angle is limited. This is because the vertical force generates mechanical stress on the blade support,
This is because the blade support will be damaged.

In the rotary cutting tool according to the invention, the optimum value range of the wedge angle α (FIG. 1) is 9°±2°.
The actual optimum value will depend on the properties of the materials from which the blade support and insert are made.

In an alternative embodiment, the insert is formed with means such as recesses 25a, 25b, 25c for receiving retaining means such as retaining detents 24a, 24b, 24c.

Therefore, the geometry of the insert with the restraining surface and the blade support allows the insert to be clamped and positioned independently of the magnitude of the cutting force. In order to remove the insertion blade, a force greater than the frictional holding force from the direction of the recess of the catch is required.

Concave surfaces 10a, 10b are advantageous over convex surfaces when the insert is made of hard metal and excessive stresses occur in the blade support. This is because the insert blade breaks before the catch of the blade support.
This is because it protects the blade support. The prismatic shape of the insert (particularly if right-hand and left-hand inserts are used alternately) increases the stability of the insert against lateral forces.

At the front of the insert there is a cutting edge 12 followed by chip forming means 13. The chip forming means 13 shapes the chip so that the width of the chip is narrower than the width of the cutting groove (FIG. 7a), hardens the chip, and curls the chip. The ridges of the insert, such as ridges 18a, 18b, begin at some distance from the cutting edge 12. As a result, the chips are
Since the chips are shaped while they are still hot and flexible due to the cutting action, the energy consumed in shaping the chips can be significantly reduced.
Furthermore, the arrangement of the protrusions creates an internal force in the chips, which deforms them into a tight spiral shape.

As the chip spiral grows, it moves upward along the plane of the insert, specifically along the inclined guide surface 26 between the chip forming part 13 and the upper holding surface (eg 10a, 11a). . The concave surface 17 acts as an extension of the inclined guide surface 26 as the chip helix moves and facilitates the removal of the chip from the workpiece. The actual chip forming part 13 is the cutting land 22 and the fifth -
Projections 18a, 18b, 2 as illustrated in FIG.
has 0. For example, the chip forming section of FIG. 5 has a cutting land 22 that continues into a recess 19 defined by two side ridges 18a, 18b. FIG. 5a is a cross-sectional view of chips formed by the chip forming section of FIG. 5. FIG.

FIG. 6 shows a chip forming part having a central protrusion 20 and cutting lands 22 continuing to flat surfaces 21a, 21b on both sides thereof. FIG. 6a shows a cross section of chips formed by the chip forming section of FIG. 6.

FIG. 7 shows a chip forming section having a central ridge 20 and two flat surfaces 19a, 19b defined by spaced side ridges. FIG. 7a shows chips formed by the chip forming section of FIG. 7 and the width of the groove of the workpiece.

A common feature of the chip forming portion of the insert blade is that the chips are molded immediately after cutting, so that the chips are narrower in width than the width of the cutting groove. The chips transform into tight coils.

Although the principles of the invention have been described in connection with particular devices and applications, this description is intended to be illustrative and not intended to limit the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a rotary cutting tool, FIGS. 2 and 3 are perspective views showing another embodiment of the catch and insert blade according to the present invention, and FIG. 4 is a perspective view of an embodiment of the removal key. Fig. 5 is a perspective view of an insert blade with a pair of side protrusions for forming chips, Fig. 5a is a cross-sectional view of chips formed by the insert blade of Fig. 5, and Fig. 6 The figure is a perspective view of an insert blade with a central protrusion for forming chips, Figure 6a is a cross-sectional view of chips formed by the insert blade of Figure 6, and Figure 7 is a cross-sectional view of the insert blade for forming chips. A perspective view of an insert having a pair of side protrusions and a central protrusion between them; FIG. 7a is a cross-sectional view of chips formed by the insert of FIG. 7;
Figures 8a, 8b, and 8c are perspective views of a catch with a spring-like detent for holding the insert blade, and Figures 9a, 9b, and 9c are perspective views of a catch provided with a spring-like detent in the catch, respectively. 1 is a perspective view of an insert according to the invention with a multifaceted recess for retention; FIG. 1... Blade support, 3... Seat, 6... Removal hole, 8... Insert blade, 18a, 18b... Side protrusion, 20... Center protrusion, 21a, 21b... Flat Bearing surface, 22...Cutting land, 24a, 24b, 2
4c...Return stop, α...Wedge angle.

Claims (1)

[Scope of Claims] 1. A metal cutting insert blade having flat top, bottom, front and side surfaces, including a right-angled cutting edge formed at the intersection of the top and front flat surfaces, and a right-angled cutting edge formed at the intersection of the top and front flat surfaces; a chip forming device formed on a surface; and a land surface separating the chip forming device from the cutting edge, the chip forming device extending inward from the land surface and being formed continuously with the land surface. Metal cutting comprising a protrusion formed on the top surface having a tip surface, the protrusion being oriented substantially perpendicularly to the cutting edge and provided in the middle of the flat surface of the side surface. Insert blade. 2. Claim 1, wherein the chip forming device further includes a pair of separate protrusions each disposed adjacent to the flank of the side surface.
The metal cutting insert described in section. 3. The metal cutting insert according to claim 1 or 2, further comprising a wedge-shaped main body portion. 4. A metal cutting insert blade having flat top, bottom, front, and side surfaces, including a right-angled cutting edge formed at the intersection of the top and front flat surfaces, and a chip formed on the top surface. a forming device and a land surface separating the chip forming device from the cutting edge, the chip forming device extending inward from the land surface and having a distal end surface formed continuously with the land surface; A metal cutting insert blade and said metal cutting tool, comprising a protrusion formed on a surface, said protrusion oriented substantially perpendicularly to said cutting edge and provided in the middle of said flat surface of said side surface. A metal cutting tool having a combination with a tool support formed with a seat for the insert in which the insert is held. 5. Claim 4, wherein the chip forming device further includes a pair of separate protrusions located adjacent to the flanks of the side surfaces.
A metal cutting tool comprising a metal cutting insert according to item 1 and a tool support formed with a seat for the insert in which the metal cutting insert is held. 6. The metal cutting insert blade according to claim 4 or 5, wherein the metal cutting insert blade further has a wedge-shaped main body portion, and the insert blade in which the metal cutting insert blade is held. A metal cutting tool having a combination with a tool support formed with a seat. 7. The metal cutting tool according to claim 4, wherein the metal cutting insert forms a wedge-shaped body portion and the seat of the insert forms a corresponding wedge-shaped groove. 8. A patent claim characterized in that the tool support is disk-shaped and has a plurality of seats provided around the outer periphery of the tool support, and a plurality of similar metal cutting insert blades are held in the seats. A rotary groove cutting tool constituting the metal cutting tool according to item 4 or 7.