JP2001079772A - Milling tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously carry out cutting and grinding with one tool concern ing a milling tool constituting a edge part by brazing diamond abrasive grains. SOLUTION: An inclined part 13 is formed at a part to an outer peripheral part 12 of an end surface of a milling tool constituting an edge part by brazing diamond abrasive grains to an end surface of a cup type base metal and its outer peripheral part, and abrasive grains 15 are arranged under a condition suitable for cutting with the outer peripheral part 12 and the inclined part 13 as a region 14 for cutting on this tool. Additionally, abrasive grains 18 are arranged under a condition suitable for grinding with a flat part 16 of the end surface as a region 17 for grinding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a milling tool using diamond abrasive grains, and more particularly to a milling tool capable of simultaneously performing rough grinding and grinding.

[0002]

2. Description of the Related Art Conventionally, as a milling tool for processing a surface of a cast alloy or a ceramic compact, a chip using diamond abrasive grains or a tool having an abrasive layer formed thereon is used instead of a cemented carbide chip. Have been.

For example, Japanese Patent Publication No. 59-50449 discloses that a cutting edge made of polycrystalline diamond formed by sintering diamond powder under high temperature and high pressure is brazed to the cutting edge of a chip body as a cutting edge for finish cutting. A face milling cutter is described. According to this milling cutter, the life of the milling cutter can be greatly improved compared to a conventional milling cutter using only a carbide tip, and even when used for a long time, a good cutting surface can always be obtained as expected. I have.

Japanese Patent Application Laid-Open No. 61-265207 describes an electrodeposition milling tool in which diamond abrasive grains are adhered to a cutting edge portion by plating. According to this milling tool, it is said that the cutting efficiency of a fragile material can be improved.

[0005] By the way, in the surface processing of, for example, an aluminum cast alloy, there are portions that require both rough grinding and grinding due to the relationship with the shape and dimensions of the final product. In order to machine such a portion, machining is performed using separate milling tools suitable for rough grinding and grinding. The milling tool described in Japanese Patent Publication No. 59-50449 has excellent wear resistance and a long life because the cutting edge is made of a diamond sintered body, but is suitable for rough grinding because the cutting edge is large. Are not suitable for grinding.
The milling tool described in Japanese Patent Application Laid-Open No. 61-265207 is suitable for grinding but not for rough grinding because the cutting edge is an abrasive layer in which diamond abrasive grains are densely fixed by electrodeposition. is there.

[0006] In the rough grinding and the grinding, there is a grain size of the abrasive grains and an interval between the abrasive grains which are suitable for each processing. JP-B-59-50449 and JP-A-61-26520.
In the milling tool described in Japanese Patent Publication No. 7, since the grain size and spacing of the abrasive grains cannot be changed in one tool, it is inevitably a tool dedicated to either rough grinding or grinding. I can't get it.

[0007]

On the other hand, concrete,
For rough grinding or grinding of hard materials such as rock, there are tools in which diamond abrasive grains are brazed to a substrate. For example, Japanese Unexamined Patent Publication No. Hei 6-210571 discloses a tool in which diamond abrasive grains are bonded by solder to a thickness-reduced region in which the thickness of a disk-shaped support is reduced toward the outer periphery. In this tool, the abrasive grains are spaced apart from each other by a predetermined pitch, and can be effectively used as a cutter disk and a groove milling mill.

However, in the case of this tool as well, since the size of the cutting blade made of abrasive grains is substantially uniform over the entire surface of the support, the action of the abrasive grains is either rough grinding or grinding. A single tool cannot perform both the coarse grinding and the grinding. That is, if the pitch of the abrasive grains is large, the abrasive grains act on the rough grinding, and as a result, the processing accuracy decreases. On the other hand, if the pitch of the abrasive grains is small, the abrasive grains act on the grinding, and as a result, the processing efficiency is reduced.

The problem to be solved by the present invention is to make it possible to perform rough grinding and grinding simultaneously with a single tool in a milling tool having a cutting edge portion formed by brazing diamond abrasive grains.

[0010]

SUMMARY OF THE INVENTION A milling tool according to the present invention is a milling tool in which a diamond-shaped abrasive is brazed to an end face of a cup-shaped base metal and an outer peripheral portion thereof to form a cutting edge. An inclined portion or a curved surface portion is formed in a portion near the outer peripheral portion, and abrasive grains are arranged under conditions suitable for coarse grinding with the outer peripheral portion and the inclined portion or the curved surface portion as a rough grinding region,
Abrasive grains are provided under conditions suitable for grinding using the flat portion of the end face as a grinding area.

In the milling tool of the present invention, the cutting edge is divided into a rough grinding area and a grinding area, and the abrasive grains are arranged under conditions suitable for each. Processing can be performed simultaneously.

Here, the abrasive grain disposing conditions suitable for each of the rough grinding and the grinding include, in the rough grinding area, increasing the spacing between the abrasive grains and increasing the grain diameter of the abrasive grains. Is to be set singly or in combination, and for the grinding area, to reduce the arrangement interval of the abrasive grains, and to set the grain size of the abrasive grains singly or in combination. That is.

In order to improve the rough grinding property of the cutting edge, it is effective to increase the bite into the work material. It is preferable to increase the interval between the grains. Specifically, it is preferable that the grain size of the abrasive grains is in the range of 0.3 to 0.5 mm, and the interval between the abrasive grains is in the range of 4 to 8 times the grain size of the abrasive grains. If the abrasive grain size is less than 0.3 mm, the penetration into the work material is small, and the heat radiation property and the chip discharging performance deteriorate. However, if it exceeds 0.5 mm, it will not be possible to secure a sufficient spacing between the abrasive grains. Also, the spacing between the abrasive grains is set to be 4 times the abrasive grain diameter.
If the ratio is less than twice, the penetration into the work material is small, and the heat radiation property and the chip discharging performance deteriorate. However, if it exceeds eight times, the number of abrasive grains acting on the rough grinding decreases, and the load on one abrasive grain increases, so that the abrasive grains are easily crushed or dropped.

On the other hand, since the ground surface is required to have a small surface roughness after processing, it is preferable that fine abrasive grains are densely arranged in the grinding area. Specifically, the abrasive particle size is 0.1 to
It is preferable that the abrasive grains have a range of 0.3 mm, and the interval between the abrasive grains is 4 to 8 times the grain diameter of the abrasive grains. Abrasive grain size is 0.3m
If it exceeds m, the bite will increase and the surface roughness will increase, and if it is less than 0.1 mm, the protrusion amount of the abrasive grains will decrease and the surface roughness will also increase. If the spacing between the abrasive grains exceeds 8 times the grain diameter of the abrasive grains, the entire machined surface is not uniformly processed, and the surface roughness is poor. If the spacing is less than 4 times, the heat dissipation and the ability to discharge chips are poor. Become. In addition, it is desirable that the heights of the abrasive grains are made uniform so that the abrasive grains in the grinding area uniformly hit the processing surface. Height alignment is obtained by truing.

The inclined portion or the curved surface portion is a transition region between the rough grinding region and the grinding region, and the inclination angle of the inclined portion is 10 to 30 degrees with respect to the flat portion of the end face of the base metal. It is desirable that the width be within the range, and that the radius of curvature of the curved surface portion be 1/2 to 2/3 times the width of the end face of the base metal. If the inclination angle is less than 10 degrees, the resistance during rough grinding increases and the machining efficiency decreases, while if it exceeds 30 degrees, the area acting on the grinding becomes small (the number of abrasive grains decreases) and the ground surface Surface roughness deteriorates. Also, the radius of curvature of the curved surface portion is 1 / the width of the end surface.
If it is less than 2, the resistance during rough grinding increases, and if it exceeds 2/3, the area acting on the grinding becomes small and the surface roughness deteriorates.

Since the greatest load is applied to the boundary between the inclined portion or the curved portion and the outer peripheral portion during rough grinding, an inclined surface or a curved surface having a larger inclination angle than the inclined portion is applied to this boundary portion. And it is desirable to dispose abrasive grains at this boundary portion more densely than other coarsely ground portions. Accordingly, a large load on the boundary portion is reduced, rough grinding can be performed with high efficiency, and a reduction in tool life can be suppressed.

In the above-described rough grinding area and the grinding area,
The diamond abrasive grains are arranged in one or more layers and brazed. Whether the abrasive grains are arranged in one layer, two layers or three or more layers can be determined depending on the use of the milling tool. For example, one layer is suitable when emphasizing the machining surface, two layers are suitable when both the machining surface accuracy and the tool life are required, and three layers are suitable when emphasizing the tool life. The above multilayers are suitable. The brazing method can be performed by a conventionally known method, and a method of including an active metal in the brazing material can also be adopted.

The milling tool according to the present invention is manufactured by the following steps. An inclined portion (or a curved surface portion) is formed in a portion near the outer peripheral portion of the end face of the base metal. A paste-like silver brazing filler metal containing titanium is applied to the outer peripheral portion, the inclined portion (or the curved surface portion), and the flat portion of the end surface. Diamond abrasive grains having a particle diameter of 400 μm are arranged at 2.4 mm intervals on the outer peripheral portion and the inclined portion (or the curved surface portion). 1.8 μm diamond abrasive grains with a particle size of 250 μm
They are arranged at mm intervals. A particle size of 40 at the boundary between the outer peripheral portion and the inclined portion (or the curved surface portion)
Diamond abrasive grains of 0 μm are arranged at 2.2 mm intervals. Heating is performed in a non-oxidizing atmosphere to fix the diamond abrasive grains on the base metal. Truing is applied to the flat part to make the height of the abrasive grains in the flat part uniform.

[0019]

FIG. 1 is a perspective view showing a milling tool according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a cutting edge of the milling tool shown in FIG.

The milling tool 10 comprises a cup-shaped base 11
An inclined portion 13 is formed at a portion of the end face near the outer peripheral portion 12,
Abrasive grains 15 are provided under conditions suitable for rough grinding, with outer peripheral portion 12, inclined portion 13 and boundary portion 13 a serving as rough grinding region 14, and conditions suitable for grinding using flat portion 16 on the end face as grinding region 17. And the abrasive grains 18 are provided.

The base metal 11 is a steel base metal having a short overall cylindrical shape, and has a mounting hole 11a at the center of the bottom for mounting to a rotating shaft of a power tool. The dimensions of each part of the tool are 100 mm outside diameter and 80 m inside diameter of the base metal 11.
m, the height of the outer peripheral part 12 is 7 mm, the width of the inclined part 13 is 5 mm,
20 degree of inclination angle of inclination part, width 5mm of flat part 16, base metal 1
1 has an overall height of 50 mm.

The outer peripheral portion 12 and the inclined portion 1 of the rough grinding area 14
3 has 2.4 diamond abrasive grains 15 having a particle size of 400 μm.
mm, and the boundary 13a has a particle size of 400 μm.
Of diamond abrasive grains 15 are arranged at intervals of 2.2 mm. In addition, diamond abrasive grains 18 having a particle size of 250 μm are arranged on the flat portion 16 at intervals of 1.8 mm.

As described above, the milling tool 10 has a rough grinding area 14 in which diamond abrasive grains are provided under conditions suitable for rough grinding, and a grinding area 17 in which diamond abrasive grains are provided under conditions suitable for grinding. , So that both rough grinding and grinding can be performed simultaneously with a single tool. For example, as shown in FIG.
In the surface machining of No. 0, by turning the milling tool 10 to the left in the drawing while rotating, the surface of the aluminum casting alloy 20 is coarsely ground and removed in the rough grinding area 14,
Next, the surface is ground in the grinding area 17.

[0024]

〔Test condition〕

 Machine used: Mitsubishi machining center (MV-5B) Table speed: 2800 m / min Wheel peripheral speed: 2500 m / min Cutting depth: 2.8 mm / pass Work material: Aluminum die-cast alloy (ADC-40)

[Test Results] Table 1 shows power consumption, tool durability and surface roughness of the ground surface, which are indicators of the grinding ability.

[Table 1] The power consumption and tool durability are indicated by an index when the conventional product is set to 100.

As can be seen from Table 1, the power consumption of the invention product is reduced by 37 to 50%, the service life is 1.2 to 2.0 times, and the grinding ability and tool life are excellent compared to the comparative product and the conventional product. ing. In addition, the roughness of the ground surface is small and the processing accuracy is excellent. In this test, the depth of cut is set according to the conventional product and the comparative product for grinding, but in the case of the invention product, since the depth of cut can be actually increased because it is also used for rough grinding, The overall grinding capability will be even higher.

[0027]

According to the present invention, the following effects can be obtained.

(1) The cutting edge portion is divided into a rough grinding area and a grinding area, and abrasive grains are provided under conditions suitable for each area, so that both rough grinding and grinding can be performed simultaneously with one tool. be able to.

(2) By setting the abrasive grain arrangement interval and the abrasive grain diameter in the rough grinding area to specific ranges, the penetration into the work material at the time of rough grinding is increased, and the amount of grinding removal is reduced. Can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a milling tool according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a cutting edge of the milling tool of FIG. 1;

FIG. 3 is a view showing a use state of the milling tool of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Milling tool 11 Base metal 11a Mounting hole 12 Outer peripheral part 13 Inclined part 13a Boundary part 14 Rough grinding area 15 Abrasive grain 16 Flat part 17 Grinding area 18 Abrasive grain 20 Aluminum cast alloy

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasushi Inoue Noritake Diamond Co., Ltd. 210, Tanushimaru-cho, Ukiha-gun, Fukuoka Prefecture Inside (72) Inventor Naoki Toge 210-No. F term (for reference) 3C063 AA10 AB02 BB02 BB07 BB23 BC02 BG03 BG10 BH05

Claims (6)

[Claims] 1. A milling tool in which a diamond-shaped abrasive is brazed to an end surface of a cup-shaped base metal and its outer peripheral portion to form a cutting edge portion, and a slope portion or a curved surface portion is formed at a portion near the outer peripheral portion of the end surface. Is formed, the outer peripheral portion and the inclined portion or the curved surface portion are provided with abrasive grains under conditions suitable for rough grinding as a rough grinding region, and the flat portion of the end surface is a condition suitable for grinding as a grinding region. A milling tool comprising abrasive grains. 2. An abrasive grain disposing condition in which an abrasive grain disposing interval in the rough grinding area is larger than an abrasive grain disposing interval in the grinding area, and an abrasive grain diameter in the coarse grinding area is 2. The milling tool according to claim 1, wherein the abrasive grain disposing conditions which are larger than the abrasive grain diameter in the grinding area are set individually or in combination. 3. The milling tool according to claim 2, wherein the intervals between the abrasive grains in the rough grinding area are set to a range of 4 to 8 times the abrasive grain diameter. 4. The abrasive grain size in the rough grinding area is 0.3 to
3. The milling tool according to claim 2, wherein said milling tool has a range of 0.5 mm. 5. The milling tool according to claim 1, wherein an inclination angle of the inclined portion of the base metal end surface is in a range of 10 to 30 degrees with respect to the flat portion. 6. The milling tool according to claim 1, wherein a radius of curvature of a curved surface portion of the end face of the base metal is 1/2 to 2/3 times a width of the end face.