JPH0232114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a work rest used to support a cutting tool such as a miniature drill or an end mill during grinding.

[Prior art]

FIGS. 6A, 6B, and 6C are a plan view, a front view, and a side view, respectively, showing the structure of a conventional work rest and its mounting base. In these figures, reference numeral 1 indicates a work rest made of carbide, and a groove portion 2 having a semicircular cross section is formed on the upper surface of the work rest, and a work rest mounting base 3 is formed on the upper surface of the work rest.
attached by brazing, organic adhesive or mechanical clamps. Screw holes 3a, 3a are formed in the lower surface of the work rest mount 3, and the mount 3 is fixed to the apparatus base with screws.

When grinding a cutting tool such as a miniature drill or an end mill, the workpiece 4 fixed to the chuck 5 is moved to the workpiece rest 1 as shown in FIG.
By rotating or moving the chuck 5 while placed on the work rest 1, the work 4 is ground by a grinding wheel from above the work rest 1 while being rotated/moved. Conventionally, this type of work rest 1 has been manufactured by directly applying a semicircular arc cross section to the upper surface of a rectangular parallelepiped carbide material by using a full-form grindstone whose outer periphery has a semicircular arc cross section. The method used was to grind the grooves.

[Problem that the invention seeks to solve]

However, in the above-mentioned work rest manufacturing method, since the groove is machined into the end face of the carbide material, when the width of the groove 2 becomes smaller than a certain level (for example, 0.3 mm), the cross-sectional shape of the outer periphery of the grinding wheel becomes As a result, it becomes extremely difficult to form the cross section of the groove 2 into an accurate semicircular arc shape with a constant depth.
In the case of a work rest for grinding a cutting tool, the tip of a cutting tool such as a miniature drill with a circular cross section is fitted into the groove 2, and the cutting tool is rotated during processing, so the groove 2 is almost completely cut. Sufficient machining accuracy cannot be obtained unless the cross section is a semicircular arc shape. Therefore, with conventional work rest manufacturing methods, it has not been possible to manufacture a work rest that can be used for grinding extremely fine cutting tools.

Further, the work rest obtained by the above manufacturing method also had the problem of wear. That is, first, when measuring the dimensions of the work 4 before processing the work 4, the work 4 is rotated or moved on the work rest 1, but at this time, the work rest 1 is worn out. Further, during processing of the workpiece 4, the workpiece 4 is ground while being rotated on the workrest 1. In this case, if the ground part of the workpiece 4 is rubbed against the workrest 1,
Furthermore, wear of the work rest 1 occurs. This is particularly noticeable when machining the tip of the workpiece 4.
As described above, when the work rest 1 wears, the machining dimensions of the work 4 change, causing product defects, so the conventional work rest 1 has had to be replaced frequently.

This invention was made in view of the above circumstances,
To provide a method for manufacturing a work rest having a groove part having an accurate semicircular arc cross section, high straightness of axis and small groove width, and having high wear resistance on the inner surface of this groove part and long life. is the issue.

[Means for solving problems]

The method for manufacturing a work rest for grinding a cutting tool according to the present invention is characterized by having the following steps.

(a) a first step of fitting and fixing a cylindrical second material made of a diamond sintered body or a CBN sintered body into the inside of the hollow cylindrical first material; (c) a third step of lapping or grinding the inner surface of the through hole; (d) ) a fourth step in which the first and second materials are cut on a virtual plane parallel to the axis that is a minute distance away from the axis of the through hole, and the portion on the axis side is used as a base; A fifth step of grinding the dividing surface of the base by the minute amount to match the axis.

〔Example〕

FIGS. 1A, 1B, and 1C are a front view, a top view, and a side view, respectively, showing a work rest 11 obtained by the method of manufacturing a work rest for grinding cutting tools of the present invention. , I will explain this first. As shown in these figures, the work rest 11 is composed of a base member 12 and a work receiving member 13. Base member 12
is a member made of carbide and having a substantially U-shaped cross section, and a workpiece receiving member 13 is attached to the concave surface of this base member 12 by adhesive or brazing. The workpiece receiving member 13 is a member having a semicircular cross section formed of a diamond sintered body or a CBN (cubic boron nitride) sintered body, and has a groove portion 14 formed in its upper surface 13a to receive the workpiece. . Then, the work rest 1 with the above configuration
1 is placed in a groove 16 formed on the upper surface of the work rest mount 15, and plates 17, 17 extend from the upper surface of the work rest 11 excluding the groove 14 to both sides of the upper surface of the work rest mount 15. The plates 17, 17 are placed on the screws 17.
a, 17a are tightened and fixed to the work rest mount 15, whereby the work rest 11 is fixed to the work rest mount 15.

In the work rest 11 having the above structure, since the work receiving member 13 is formed of a diamond sintered body or a CBN sintered body, the groove part 14 wear is much less and therefore its life is significantly increased (about 100 times or more).

In the above embodiment, the work rest 11 is made of a diamond sintered body or a CBN sintered body, but it may be made of natural diamond instead. Further, the base member 12 may be formed of a steel material (carbon steel for mechanical structures, stainless steel, carbon tool steel, high speed steel, alloy tool steel, high carbon chromium bearing steel).

FIG. 2 shows an example of the shape of a miniature drill, and FIG. 3 shows an example of how the work rest 11 is used when grinding the miniature drill shown in FIG. 2.

Further, FIG. 4 shows an example of the shape of the groove portion 14. When grinding a tapered miniature drill, the groove 14 is also tapered as shown in this figure.

Next, an embodiment of the work rest manufacturing method according to the present invention will be described with reference to FIG.

First, a material 18 made of a cylindrical diamond sintered body or a CBN sintered body shown in FIG. 5A is inserted and fixed into a hollow cylindrical carbide material 19 shown in the same figure. In this case, fixing is done by brazing or gluing.

Next, the material 20 formed by the above process
Surface grinding is performed on the upper and lower surfaces 20a and 20b (see FIG. 5B).

Next, the peripheral surface 20c of the material 20 shown in FIG.
Perform cylindrical grinding.

Next, as shown in FIG. 5D, a through hole 21 is formed in the center of the material 20 by electric discharge machining or laser machining, and then the inner surface of the through hole 21 is lapped.

Next, as shown in FIG. 5E, the material 20 is divided on a virtual plane 22 parallel to the axis 21a of the through hole 21, which is a minute distance away from the axis 21a, and unnecessary parts (shaded parts) are removed. . In this case, the division is carried out by grinding, electric discharge or laser. Note that the dimension a in the figure is the cutting allowance, and is, for example, 0.005 to 0.5 mm.

Next, as shown in FIG. 5, the dividing surface 23 of the semi-cylindrical material formed by the above process is finished and flattened.

Through the above steps, the work rest is completed.

Incidentally, after the above steps are completed, surface grinding of the upper and lower surfaces 20a and 20b may be performed in order to eliminate the widening at both ends of the through hole 21 that is likely to occur due to lapping. Also, the diameter of the through hole is 0.2
For lapping of large diameters of mm or more, internal grinding may be performed.

〔Effect of the invention〕

As explained above, according to the method of manufacturing a work rest for cutting tool grinding according to the present invention, after the second material is fitted and fixed inside the hollow cylindrical first material, the central axis of the second material is A through hole with a circular cross section is formed by laser processing, and the inner surface of this through hole is lapped or ground.
A through hole having a small inner diameter, high roundness in cross section, and high straightness of the axis can be formed in the extremely hard second material made of a diamond sintered body or a CBN sintered body. In addition, since the material is divided on an imaginary plane parallel to the axis that is slightly away from the axis of the through hole, and then the surface is ground to a position that coincides with the axis to form the groove, the roundness and straightness of the through hole are completely lost. It is possible to form grooves with a semicircular arc cross section without any grinding, which could not be achieved with conventional full-form grinding methods.
It is possible to easily form a groove with a perfect semi-circular cross-section, high axis straightness, and small width.

In addition, according to this manufacturing method, since the inner surface of the groove is made of diamond sintered body or CBN sintered body, its wear resistance can be significantly increased, and the life of the work rest can be significantly extended. is possible.

[Brief explanation of drawings]

1A to 1C are a plan view, a front view, and a side view of a work rest 11 according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of the shape of a miniature drill, and FIGS. 4 is a diagram showing an example of the use of a work rest when grinding a miniature drill, FIG. ,
6A to 6C are a plan view, a front view, and a side view of a conventional work rest 1, respectively, showing a method of manufacturing a work rest 11 according to an embodiment of the present invention. 4...Miniature drill, 5...Chick, 11...
Work rest, 12... Base member, 13... Work receiving member, 14... Groove, 15... Work rest mounting base, 17... Plate, 18... Material made of diamond sintered body or CBN sintered body, 19... Carbide material, 20...Material, 21...Through hole, 21a...Axis line,
22...Virtual surface.

Claims (1)

[Claims] 1 (a) A first step of inserting and fixing a cylindrical second material made of a diamond sintered body or a CBN sintered body into the inside of a hollow cylindrical first material; (b) a second step of forming a through hole with a circular cross section by laser processing along the central axis of the inserted second material; (c) a second step of lapping or grinding the inner surface of the through hole. (d) cutting the first and second materials on a virtual plane parallel to the axis that is a minute distance away from the axis of the through hole, and cutting the first and second materials on a virtual plane parallel to the axis line, and cutting the first and second materials on a virtual plane parallel to the axis line, and cutting the first and second materials on a virtual plane that is parallel to the axis line, and (e) a fifth step of grinding the dividing surface of the base by the minute amount and aligning it with the axis line.