JPS6314962Y2 - - Google Patents

Description

[Detailed description of the invention] When mass producing metal products that have relatively simple concave grooves such as arcuate or trapezoidal grooves on the outer or inner diameter surface, the throw-away has a nose that serves as the cutting edge in a shape that corresponds to the groove. Clamp-type cutting tools in which a chip (hereinafter referred to as a chip) is removably fixed to the front end of a shank using a presser foot are widely used, but there are difficulties in ejecting chips.

In other words, this type of clamp-type cutting tool uses a triangular or square tip, and has a breaker groove on the tip that is connected to the rake face of the nose and rises backwards.
The breaker surface of the presser foot, which rises further rearward following the rear end of the breaker groove of the chip, curls chips from the workpiece upward and discharges them. The chips are then sent backward along the breaker surface of the presser foot and are tangled and cut at the top, not only damaging the machined surface of the workpiece, but also getting entangled with various parts of the cutting tool, interrupting the work, and in extreme cases, chipping. There was a drawback that exposed parts were damaged, leading to damage.

This problem is caused by a straight line formed on the top surface of the tip at the end of the breaker groove that connects to the rake surface of the tip, and a breaker surface at the front end of the presser foot that engages with the end of the breaker groove, at the nose of the tip. By tilting the center line so that it intersects with the center line, the chips from the workpiece curled upward are aligned with the breaker groove of the chip and the breaker surface of the presser foot. It is thought that this can be solved by lowering the chip and ejecting it to the side, but in the case of the triangular or square chips mentioned above, the nose adjacent to the nose facing the workpiece protrudes significantly to the side. The flow of chips, which are curled like a spring with their own weight and whose direction is changed by the breaker groove and the breaker surface, produces irregular undulations on the exposed upper surface of the chip, especially on the adjacent nose. Therefore, no satisfactory results were obtained.

The present invention is intended to solve the above-mentioned drawbacks, and the embodiments shown in the drawings will be described below.

In the figure, reference numeral 1 indicates an oval chip made of ceramic, cermet, or cemented carbide. Here, a rake surface 11a at the tip is attached to the first nose 11, which becomes an arc-shaped cutting edge corresponding to the arc-shaped groove to be formed on the outer diameter surface.
Then, a breaker groove 11b is formed that extends rearward from the rake surface 11a and reaches the upper surface of the chip 1. However, the straight line 11c formed when the breaker groove 11b reaches the upper surface of the chip 1 is the longitudinal direction of the chip 1. It is not perpendicular to the axis of the direction, but is inclined in any direction, in this case, to the lower right. Also,
Second nose 12 at the longitudinal rear end of the tip 1
Then, the rake face 12a, the breaker groove 12b, and the breaker groove 1 are arranged so that when it is rotated 180 degrees, it faces the workpiece in the same state as the first nose 11.
A straight portion 12c at the upper end of 2b is formed. 2 is a presser foot having a breaker surface 21;
The front end 21a of 1 is connected to the breaker groove 11b of the chip.
Similar to the straight line portion 11c at the rear end, it is not perpendicular to the axis but is tilted so that it is located on the same line as the straight line portion 11c at the rear end of the breaker groove or slightly rearward thereof, and its rising angle is It should be made equal to or slightly steeper than the breaker groove 11b of the chip. Reference numeral 3 denotes a shank having a catch seat 31 bored in the front end for abutting and seating the oval-shaped chip 1 on its both sides and rear end. The ends of the breaker groove 11c and the breaker surface 21 of the presser foot are located on the side far from the tip nose 11, respectively.
In this case, it is desirable to provide it close to the lower side wall 32 and to make the side thickness between the side wall 32 and the inner wall 33 that fits into the side wall of the chip as small as possible. Although not shown in the drawings, the shank is linear when forming the groove on the outer diameter surface of the workpiece, and is bent at an appropriate angle when it is formed on the inner diameter surface. Reference numeral 4 denotes a mounting bolt for fastening and fixing the chip 1 housed in the seat 31 of the shank and the presser foot 2 placed on its upper surface.

Since the clamp type cutting tool of the present invention is constructed as described above, chips from the workpiece are curled by the breaker groove of the chip and sent backwards, not perpendicular to the axis but in any direction. In the figure, the chips are ejected by being deflected toward the lower right along the breaker groove and the breaker surface of the presser foot, which are tilted toward the lower right.However, the chips are oval-shaped and are different from conventional triangular or square shapes. Since it does not have side protrusions like chips, the chips are discharged in a continuous state without getting tangled, which eliminates the various drawbacks of conventional products mentioned above, and especially forms deep grooves in the workpiece. If you do,
Furthermore, even when a plurality of grooves are simultaneously formed at small intervals, it is highly effective in preventing entanglement of adjacent chips.

Although not shown, a strip-shaped protrusion with a triangular or inverted trapezoidal cross section is provided on the bottom surface in the longitudinal direction of the chip, and a groove that fits with this protrusion is formed on the upper surface of the seat of the shank. It can securely fix the chip and increase durability.

In addition, in order to further smooth the flow of chips, the front end of the lower side wall in the chip discharge direction that constitutes the catch at the tip of the shank is partially or completely extended from near the rear end of the breaker surface of the presser foot. It may be cut out.

[Brief explanation of the drawing]

FIG. 1 is a top view showing the main parts of the clamp-type cutting tool of the present invention, and FIG. 2 is a sectional view taken along line E--I in FIG. 1. 1... Chip, 11, 12... North, 11
a, 12a... rake face, 11b, 12b... breaker groove, 11c, 12c... end of breaker groove, 2... presser foot, 21... breaker surface, 3...
Shyank.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A throw-away tip equipped with multiple noses that serve as cutting edges that form grooves of a desired shape on the inner and outer diameter surfaces of a workpiece is shank using a presser foot. The throw-away tip is of an oval shape with noses at both ends in the longitudinal direction, and the end of the breaker groove connected to the rake face of the cutting edge provided on the nose, and the tip of the breaker groove are attached to the tip. The breaker surface of the front end of the presser foot that engages with the end is tilted so that it intersects the center line connecting the nose of the throwaway tip on a plane without being perpendicular to it, and the front end of the breaker surface of the presser foot is thrown. A clamp-type cutting tool characterized by being aligned with the end of the breaker groove of the away tip or located at the rear. (2) The clamp-type tool bit according to claim 1, which is a utility model registration, in which a band-shaped projection is provided on the lower surface in the longitudinal direction of the throw-away tip, and is fitted into a corresponding groove formed on the upper surface of the shank.