JPH0436803B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention uses a high-hardness sintered body such as CBN (high-pressure phase boron nitride) sintered body or PCD (sintered diamond) as the cutting edge material. In some cases, the economic effect is significant,
The present invention also relates to a cutting tool with excellent holding stability of the cutting edge tip by a holder, and a method of manufacturing the cutting edge tip for the same.

[Conventional technology and its issues]

Since high hardness sintered bodies as mentioned above are expensive,
In cutting tools that use this as a cutting edge,
What is important is whether the sintered body can be used without waste.

However, conventional cutting tools of this type with a cutting edge angle are wasteful in the use of sintered bodies. That is, conventionally, as shown in FIG. 6, a chip 1 made of a high-hardness sintered body is cut out from a material in the form of a cube, the bottom surface 1a and the back surface 1b are brazed to the holder 2, and then the front flank surface and the The chain line part of the front surface 1c is ground at an angle of α to give a cutting edge angle β, and the front surface and top surface 1d after grinding are
A method is adopted in which the intersecting edges of the two are used as the main cutting edge.

However, with this structure, the effective range of use by re-polishing the chip is the value shown by a in FIG.・Expensive materials corresponding to the volume required by S are wasted.

Furthermore, since the amount of grinding on the front surface is large, the grinding process requires a lot of effort and time, and the amount of wear per chip of the expensive diamond grindstone is also large. Therefore, a cost disadvantage cannot be avoided.

In addition, since CBN sintered bodies and PCD are materials that are difficult to attach brazing materials to, it is said that the brazing strength is likely to be insufficient, especially when the cutting edge chips formed with these materials are small in size. There are also problems.

Therefore, an object of the present invention is to provide a cutting tool that can efficiently cut chips from a material, can be used without waste, is economical, and can easily ensure brazing strength, and a method for manufacturing the cutting edge chips used therein. There is.

[Means to solve the problem]

In order to achieve the above object, the present invention provides the first
As shown in the figure, the front surface 1c along one side of the top surface 1d of the quadrangle intersects the top surface at an acute angle, and the back surface 1b along the side parallel to the above-mentioned side of the top surface has a cutting edge 1 that is almost parallel to the front surface. The bottom surface 1a and back surface 1b parallel to the top surface of the chip are fixed to the restraining surfaces 3a and 3b of the chip mounting recess 3 provided in the holder 2, and the ridge 1e where the surfaces 1c and 1d intersect is cut mainly. Now used as a blade. Furthermore, at least one of the two surfaces 1a and 1b of the restraint surface 3 to be brazed to 3b is left with a cut surface formed by the discharge wire cut.

Further, the cutting blade tip 1 was manufactured in the following manner.

That is, a bar 4 having a rectangular cross section as shown in FIG. 2 is cut out of a material whose at least the upper surface side is made of a high-hardness sintered body, and then this bar is cut by the discharge wire cutting method ( The bar is also cut out using this method), and by making fine cuts at an angle of β and a depth of a, a chip 1 of W'÷a is cut out.

In this way, the dimensions of the chip 1 can be minimized and the efficiency of cutting out the material can be improved.

Furthermore, since the tip 1 is given an angle of approximately β when cutting, the amount of grinding required to form the cutting edge angle is extremely small.

On the other hand, machining with a slope as shown in FIGS. 2c and 1b has almost no difference in time compared to machining without a slope. By using a discharge wire cutter, a high-hardness sintered body can be cut efficiently without taking much time, regardless of whether the body is inclined or not.

In addition, since the total area of the back surface 1b increases compared to the conventional one due to the slope of that surface, the bottom surface 1a
The discharge wire cut surface left on either or both of the back surface 1b is moderately rough and increases the bonding force with the soldering material, thereby increasing the brazing strength of the chip, which affects the tool life.

Note that the cutting edge angle β of the tip 1 is preferably about 85 to 30 degrees.

Further, the upper surface 1d of the chip may be rectangular or square, or may have a shape in which one diagonal corner is an acute angle and the other diagonal corner is an obtuse angle (that is, a parallelogram).

Furthermore, at least one of the side surfaces 1f and 1g shown in FIG. 2 may be ground to intersect with the upper surface 1d and the front surface 1c at an acute angle.

Note that when a bar as shown in FIG. 2 is cut from a material whose top and bottom surfaces are both made of high-hardness sintered material, the bottom surface will also be cut.

〔Example〕

In FIG. 3, A is a side view of the cutting tool of the first embodiment used for partition cutting of hole surfaces, groove surfaces, etc., B is a front view thereof, and C is a side view when A is rotated by 90°. On the outer periphery of the tool body 6 including the shank 5, two chip mounting recesses 3 extending in the tool axis direction along the pocket 7 are provided at 180 degrees apart positions. Then, in the recess 3 where the surfaces 3a and 3b intersect at approximately the same angle as β, the cutting edge tip manufactured by the method of the present invention, that is, the front surface 1c and the rear surface 1b where the cut surface formed by the discharge wire cut is left, is approximately inserted. Chip 1 which is parallel is the bottom surface 1a
and the back side 1b are soldered and fixed. The cutting edge of this tool has a radial front clearance angle γ, a circumferential front clearance angle δ, and an outer circumferential clearance angle ε. Of these three clearance angles, γ and ε are determined by the distance from the material bar. It can be attached when cutting out chips. However, the γ of the illustrated tool was added by grinding after the chip was attached.

FIG. 4 shows an example of application to a blade that is detachably attached to a tool body. That is, the inclined clamping surface 8
and a blade body 10 having a blade edge position adjustment screw 9.
A recess 3 is provided at the tip of the upper surface, and the upper surface 1d is placed in the recess.
Chips 1 obtained by the method of the present invention, in which one diagonal corner is an acute angle, the other diagonal corner is an obtuse angle, and the front surface 1c and the back surface 1b are substantially parallel, are soldered together.

FIG. 5 shows that notched grooves 12 and chip mounting recesses 3 that open into the grooves are provided on the outer periphery of a flat plate-like main body 11 at regular pitches in the circumferential direction, and each recess 3 is provided with a chip-mounting recess 3 that is provided at regular pitches in the circumferential direction. This figure shows a circular cutter formed by brazing the chip 1.

As can be seen from these examples, the cutting edge chips obtained by the method of the present invention can be used in cutting tools for various purposes, and their retention is not limited to the tool body.
This can be done by another member detachably attached to the main body.

Furthermore, in the illustrated chip 1, only the top side is formed from a high-hardness sintered body, and the bottom side is formed from a base metal such as a WC-based alloy that is integrated during the manufacture of the sintered body. As shown, the chip 1 of the present invention is effective not only for manufacturing a chip made entirely of a high-hardness sintered body, but also for manufacturing a chip made of a general sintered alloy.

〔effect〕

As described above, according to the present invention, a bar with a rectangular cross section is cut out of a material using the discharge wire cutting method, and the bar is further cut into pieces with a constant width in the longitudinal direction along a line having a constant angle with respect to the upper surface. Since the chip is cut to have a front surface and a back surface that are substantially parallel to each other at an acute angle to the upper surface, the size of the chip can be minimized and the efficiency of cutting from the material can be increased.

Furthermore, since the grinding allowance after cutting becomes extremely small, the grinding process becomes easier and faster, and the consumption of expensive grindstones is reduced. Therefore, a low-cost tool can be realized.

In other words, since the clearance angle on the flank side is preset, there is no need for machining to obtain the required clearance angle, and the tool can be easily completed by simply removing the deteriorated layer during chip cutting. I can do it. Therefore,
The cost required for tool grinding can be reduced to 1/5 or less.

Furthermore, by sloping the back surface of the chip, the bonding area to the holder is increased, and at least one of the two surfaces to be brazed is left with the discharge wire cut surface, which improves the adhesion of the brazing material. Therefore, the strength for brazing, etc. is also improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the basic structure of a tool whose cutting edge is made of chips manufactured by the method of the present invention;
The figure is a perspective view showing an example of a method for cutting out chips;
A, B, and C of FIG. 3 are views showing the side surface, end surface, and side surface from a 90° perspective of the finishing cutting tool of the first embodiment in which the cutting edge was constructed with chips obtained by the method of the present invention.
Figure 4 is a perspective view of a tool for other purposes,
FIG. 6 is a perspective view of a conventional tool using a high-hardness sintered chip, and FIG. 7 is a sectional view thereof. 1... Chip, 1a... Bottom, 1b... Back,
1c...Front surface, 1d...Top surface, 1e...Main cutting edge ridge, 1f, 1g...Side surface, 2...Holding body, 3...
Chip mounting recess, 3a, 3b...chip restraining surface.

Claims (1)

[Scope of Claims] 1. The front side along one side of the top surface of the rectangle intersects the top surface at an acute angle, and the back side along the side parallel to the above side of the top surface is almost parallel to the front surface, and at least the top side is made of high hardness annealing. A cutting tip formed by the solid body and having at least one side cut by the discharge wire cut out of the bottom surface parallel to the back surface and the top surface is attached to a holder having the bottom surface and the restraining surface on the back surface. A cutting tool that is secured to the chip mounting recess with brazing, and the intersecting ridges on the front and top surfaces are used as the main cutting edge. 2 A bar with a square cross section is cut out from a material whose upper surface is made of high-hardness sintered material using the discharge wire cutting method, and then cut to a certain width in the longitudinal direction along a line that has a certain angle to the upper surface using the discharge wire cutting method. Then, cut the rectangle even more finely so that the front side along one side of the top surface intersects the top surface at an acute angle, and the back side along the side parallel to the above side of the top surface is almost parallel to the front surface, and the edge where the front surface and the top surface intersect is A method for manufacturing a cutting tool tip, which obtains a cutting tip that serves as a main cutting edge.