JP2002066828A - Throwaway ball end mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the conventional problem of cutting accuracy being reduced by the error of mounting a tip inside out, by preventing such an erroneous mounting. SOLUTION: This throwaway ball end mill of the type clamping a cutting tip between a pair of clamping pieces has engagement steps 6 and 10 provided respectively on the tip clamping surface 8 of one of the clamping pieces 4 and on the tip 2. Alternatively, the tip clamping surfaces 8 and 8 of both clamping pieces 4 and 4 and the tip 2 have respective engagement steps 6, 6, 10 and 10, with the pairs of engagement steps 6 and 6 and 10 and 10 and pairs of ridge lines 7 and 7 and 11 and 11 formed to deviate from each other and/or have different shapes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a throw-away type ball end mill.

[0002]

2. Description of the Related Art An end mill is a kind of milling tool and has a cutting edge on its outer periphery and has a wide range of uses such as bottom cutting, side cutting, contour copying, and groove cutting. Among these end mills, a replaceable cutting edge (a throw-away type) end mill is used by attaching a replaceable cutting edge to a tool tip, and is selected according to various shapes in die machining and component machining.

[0003] Among them, a ball end mill having an R-shaped cutting edge is a tool that can perform machining in all directions including thrusting by three-dimensional machining such as a die. As a finishing ball end mill, one cutting tip is used. The mainstream is a type in which is fixed by sandwiching it at the tip of a tool, and the blade diameter tolerance and the R accuracy are made high.

[0004] In such a throw-away type ball end mill, two clamp pieces are provided opposite to each other at the tip of the end mill body, and a cutting tip is arranged between the two clamp pieces and fixed with a clamp screw. . The chip holding surface of the clamp piece was a flat surface with no step. Therefore, in the conventional throw-away type ball end mill, it is possible to mount and fix the cutting tip even if the cutting tip is turned upside down.

[0005]

However, it is impossible to completely match the left and right shapes of the cutting tip used for the ball end mill due to the manufacturing process, and the difference between the left and right sizes is, for example, about 1/100 mm. Inevitably exists.

For example, the symmetrical position on the left and right is 0.0
When the cutting tip is displaced by 1 mm and the cutting tip is mounted upside down on a throw-away type ball end mill, a deviation of 0.02 mm occurs when comparing the respective cutting edge positions. As described above, in the conventional throw-away type ball end mill, it was used without being aware of the front and back of the cutting tip, so when performing precision machining,
In some cases, the deviation of the cutting edge position affects the processing accuracy and exceeds the allowable range of the processing accuracy.

The present invention has been made in view of such a problem of the conventional apparatus, and prevents a wrong mounting of a chip from the front and back, thereby solving a conventional problem that a processing accuracy is reduced due to a wrong mounting on the front and back. It is an object of the present invention to provide a throw-away type ball end mill.

[0008]

In order to achieve the above object, a throw-away type ball end mill according to claim 1 is provided.
At the tip of the ball end mill body, two clamp pieces are provided so as to face each other, a cutting tip having a clamp hole is disposed between the clamp pieces, and the clamp piece is penetrated from one side of the clamp piece through the clamp hole. A throw-away type ball end mill for fixing a cutting tip by screwing a clamp screw to the other side of the clamp piece, comprising a chip holding surface of the one clamp piece and an engaging step portion on the cutting tip. It is characterized by the following.

According to a second aspect of the present invention, there is provided a throw-away type ball end mill provided with two clamp pieces facing each other at a tip end of a ball end mill body, and a cutting tip having a clamp hole between the clamp pieces. In the throw-away type ball end mill of the type, the chip holding surfaces of both the clamp pieces and the cutting tip are provided with an engagement step, and the ridge lines of the two engagement steps are misaligned or formed in different shapes. It is characterized by being.

[0010] According to such a configuration, it is impossible to mount the cutting tip upside down, and therefore, it is possible to solve the problem of a reduction in processing accuracy due to mounting the cutting tip upside down.

The throw-away type ball end mill according to the third aspect of the present invention is characterized in that a ball end mill body has
In a throw-away type ball end mill of a type in which two clamp pieces are provided so as to face each other and a cutting tip having a clamp hole is provided between the clamp pieces, the engagement between the chip holding surface of both clamp pieces and the cutting tip is performed. A stepped portion, and the ridge lines of the two engaging step portions are linearly inclined obliquely to the longitudinal direction of the ball end mill, and the ridge lines of both the engaging step portions are parallel to each other. I do.

According to such a configuration, both the engagement step portions can be formed by one processing of the end mill, which is advantageous in manufacturing and manufacturing costs.

[0013]

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

FIG. 1 is a view showing a cutting tip portion of a throw-away type ball end mill of the present invention, FIG. 2 is a perspective view showing only the end mill body of the cutting portion, and FIG.
It is the arrow A view and the BB arrow view.

1 to 3, reference numeral 1 denotes a ball end mill main body, 2 denotes a cutting tip, 3 denotes a clamp screw, and 4 denotes a clamp piece.

The end mill body 1 has a circular, elliptical or polygonal cross section, and has two clamp pieces 4 on both sides of the tip.
4 are provided so as to face each other in the length direction of the main body 1.

[0017] The two clamp pieces 4, 4 are
Are formed at predetermined intervals so as to be the same as or slightly wider than the thickness of the first. Further, the length is formed so that the cutting tip 2 slightly protrudes from the front end portion and the peripheral edge portion.

As shown in FIG. 2, the tip holding surface 8 of each of the clamp pieces 4 is provided with an engaging step 6 for engaging with the cutting tip 2, and the engaging step 6 of the two clamp pieces 4, 4 is provided. The ridge lines 7, 7 of 6 are formed so as to be displaced as shown in FIG.

In this embodiment, as shown in FIG. 3, the ridge line 7 of the engaging step 6 provided on the clamp piece 4 is a straight line inclined obliquely to the longitudinal direction of the ball end mill body 1. In addition, the ridgelines 7, 7 of the two engagement steps 6, 6 are parallel.

According to such a configuration, the two engaging step portions 6 can be formed by one processing of the end mill, which is advantageous in manufacturing and manufacturing cost.

A screw hole 6a through which the clamp screw 3 is inserted is provided on one side of the two clamp pieces 4, 4, and a screw hole 6b into which the clamp screw is screwed is provided on the other clamp piece 4. ing.

The tip of the clamp piece 4 is provided in an arc shape so that a cutting tip 2 described later projects substantially evenly from the tip of the clamp piece 4.

The opposing surfaces of the clamp pieces 4, 4 are chip holding surfaces 8, 8, which come into contact with and hold the cutting chip 2 inserted between the clamp pieces 4, 4.

The end mill body 1 is made of, for example, carbon steel.

The cutting tip 2 is, as shown in FIG.
A cutting edge portion 2a formed in an arc shape such that one end side slightly protrudes from the clamp pieces 4 and 4 of the end mill body 1.
Is formed in a substantially V-shape so as to abut on the substantially V-shaped restraining surface 1a of the end mill main body 1 located rearward in the clamp pieces 4 and 4. Bottom 2b.

The bottom portion 2b is positioned in contact with the restraining surface 1a of the end mill body 1.

As shown in FIG. 4, a clamp hole 5 for fixing the cutting tip 2 to the clamp pieces 4 and 4 with a clamp screw 3 is provided at a substantially central portion of the cutting tip 2. The clamp hole 5 of the cutting tip 2 is opened, and two clamped surfaces 9 that abut against the clamp pieces 4 of the end mill body 1 have a substantially V-shaped portion on the rear end side of the cutting tip 2. An engaging step 10 configured to engage with the engaging step 6 is formed.

The engaging step portions 10 are formed so as to be misaligned or irregularly shaped on the front and back sides of the one held surface 9 and the other held surface 9.

In this embodiment, as shown in FIG.
The ridge line 11 of each engaging step 10 of the cutting tip 1 is a straight line that is obliquely inclined with respect to the major axis direction of the cutting tip 1. Furthermore, the ridgelines 11 of the two engaging steps 10 are parallel.

The cutting tip 2 is made of, for example, a cemented carbide,
It consists of cermets, coated carbide tools, ceramics, or ultra-high pressure sintered bodies.

According to such a configuration, it is impossible to mount the cutting tip upside down, and therefore, the problem of a decrease in processing accuracy due to mounting upside down is solved.

FIGS. 6 to 8 show another embodiment of the present invention. In the example shown in FIG. 6, the ridge line 7 of the engaging step 6 provided on the chip holding surface 8 of one clamp piece 4 is viewed in plan. , The ridge line 7 of the engaging step 6 provided on the other clamp piece 4 has an arc shape in plan view. In the example shown in FIG. 7, the ridge lines 7 of both the engagement step portions 6 are linear, but are displaced.

The example shown in FIG.
Only the engagement step 6 is provided.

According to such a configuration, in any case, it is impossible to mount the cutting tip 1 upside down, and therefore, it is possible to solve the problem of a decrease in processing accuracy due to mounting the cutting tip 1 upside down.

[0035]

As described above, according to the present invention, a type in which two clamp pieces are provided at the tip of the ball end mill body so as to face each other, and a cutting tip having a clamp hole is provided between the clamp pieces. In the throw-away type ball end mill, by providing the chip holding surface of the one clamp piece and the engaging step on the cutting tip, or so that the two clamp pieces are opposed to the tip end of the ball end mill body. In a throw-away type ball end mill of a type in which a cutting tip having a clamp hole is provided between the clamp pieces, an insert step portion is provided on the tip holding surface of the both clamp pieces and the cutting tip, and the two engaging members are provided. The misalignment or irregular shape of the ridge line at the stepped joint prevents incorrect mounting of the cutting tip, Machining accuracy can solve the conventional problem of a decrease by mistake.

Further, according to the present invention, a throw-away type of a type in which two clamp pieces are provided at the tip of the ball end mill body so as to face each other, and a cutting tip having a clamp hole is provided between the clamp pieces. In the ball end mill, by making the tip holding surface of both clamp pieces and the ridge line of the engaging step provided on the cutting tip parallel,
The two engaging steps provided in the clamp piece can be formed by a single operation of the end mill, which is advantageous in terms of manufacturing and manufacturing costs.

[Brief description of the drawings]

FIG. 1 is a plan view showing a tip portion of a ball end mill of the present invention.

FIG. 2 is a perspective view showing a tip portion of the ball end mill main body of FIG. 1;

FIGS. 3 (a) and 3 (b) are respectively a view as seen from arrows AA and BB in FIG. 2;

FIG. 4 is a perspective view of a cutting tip mounted on the ball end mill of FIG. 1;

5 (a) and 5 (b) are views taken in the direction of arrow C in FIG.
It is an arrow view.

FIG. 6 is a view corresponding to FIG. 3, showing another embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 3, showing another embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 3, showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball end mill main body 1a Restraining surface 2 Cutting tip 2a Cutting edge part 2b Bottom part 3 Clamp screw 4 Clamp piece 5 Clamp hole 6 Engagement step 7 Ridge 8 Chip clamping surface 9 Clamping surface 10 Engagement step 11 Ridge

Claims (3)

[Claims] 1. A cutting end having two clamp pieces provided at a tip end of a ball end mill main body so as to face each other, and a cutting tip having a clamp hole is disposed between the clamp pieces. A throw-away type ball end mill for fixing a cutting tip by screwing a clamp screw to the other side of the clamp piece through a hole, wherein a step for engaging the tip holding surface of the one clamp piece and the cutting tip is provided. A throw-away type ball end mill characterized by having a part. 2. A clamp tip is provided at the tip of a ball end mill main body so as to face each other, and a cutting tip having a clamp hole is disposed between the clamp pieces. A throw-away type ball end mill for fixing a cutting tip by screwing a clamp screw to the other side of the clamp piece through a hole, wherein a step for engaging the tip holding surface of both the clamp pieces and the cutting tip is provided. Wherein the ridges of the two engaging steps are displaced or formed in different shapes. 3. The ridge line of the engaging step of the two clamp pieces is a straight line inclined obliquely to the longitudinal direction of the ball end mill, and the ridge lines of the two engaging steps are parallel. The throw-away type ball end mill according to claim 2, characterized in that: