JPS6179574A - Grinding wheel for grooving - Google Patents

Abstract

PURPOSE:To prevent surface roughness in a groove internal surface from deteriorating even if an expensive wheel layer of a first grinding tip is used, insomuch that it is considerably thinned up, by grinding an unremoved part at the thin first grinding tip with a thick second grinding tip. CONSTITUTION:A grooving wheel being attached to a wheel spindle S is rotated, giving it infeed, and inserted into a groove of a work W, giving it traverse feed this time, then grinding takes place so as to cause a groove inner surface Wa to be adjusted to each breadth B1 of first and second wheel layers 21a and 22a by end faces 21c and 22c of a grinding tip. Each outer circumferential surface of these wheel layers 21a and 22a is trued by a dresser whereby even if thickness of the wheel layer 21a of the most part of the first grinding tip 21 becomes thinned, thickness of the wheel layer 22a of the rest second grinding tip 22 is thick enough so that an unremoved part due to insufficient grinding by the end face 21c of the thin wheel layer 21a is ground with action of the end face 22a of the thick wheel layer 22a, thus surface roughness in the groove inner surface is prevented from deteriorating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grindstone for grooving in which a large number of fan-shaped grinding chips are adhered at equal intervals to the outer periphery of a disc-shaped holder.

[Prior art]

The grinding tip of this type of groove grinding wheel consists of an expensive grinding wheel layer located on the outside of the radius and an inexpensive base layer that is narrower than the grinding wheel layer and located on the inside of the radius. The grinding tip is bonded to the holder using the conventional grinding tip, and in the conventional type, all the grinding tips have the same size.

[Problem that the invention attempts to solve]

This type of grooving whetstone is used while making corrections by cutting the outer peripheral surface with a dresser if the corner of the tip of the end face that performs the grinding action of the grinding tip becomes rounded and the grinding resistance increases. However, each time this correction is made, the thickness of the grindstone layer decreases, and when this thickness becomes less than this, the inner surface [11] of lδi ground by the end face of the grindstone layer becomes large.

For this reason, in order to prevent the conventional '/R, fjl, and l grinding stones from increasing in surface roughness, it is necessary to replace them when a considerable amount of the curved grindstone layer remains. arise,
There is a problem in that the expensive grindstone layer is wasted and the cost of the groove processing grindstone increases. The present invention attempts to solve these problems.

[Means for solving problems]

The present invention provides a grindstone for groove machining of this type, as shown in FIGS. 1 to 3.
As shown in the figure, a grinding wheel layer 21 serves as a plurality of grinding chips 20.
a; 6<Using a large number of first grinding chips 21 in which the base layer 21b is thin and thick, and a small number of second VR grinding chips 22 in which the grinding layer 22a is thick and the base layer 22b is thin,
This second grinding tip 22 is arranged between the first grinding tips 21 at equal intervals.

[Effect]

The rotating grindstone for groove machining of the present invention is given cutting feed and traverse feed, and the first and second grinding chips 21
．． End surfaces 21c and '22c of the grinding layers 21a and 22a of 22
The inner surface Wa of the groove of the workpiece W is ground by. The portion left behind due to insufficient grinding due to the end face 21c of the thin first grinding tip 21 is replaced by the thick second grinding tip 22.
is ground by the end face 22c.

[The fruit of invention]

According to the present invention, as described above, the portion left behind by the thin first grinding tip is ground by the thick second grinding tip, so the outer circumferential surface of the groove grinding wheel is modified to remove the first grinding tip that occupies the majority. Even if the expensive grinding wheel layer is used until it becomes considerably thin, the surface roughness of the inner surface of the groove will not decrease. Therefore, without reducing the surface roughness of the machined surface,
The cost of the 1R grinding wheel per workpiece can be reduced.

〔Example〕

In the embodiment shown in FIGS. 1 to 3, the grooving whetstone consists of a solid holder 10 and 12 fan-shaped grinding tips 20 adhesively fixed to the outer periphery 13 of a disk portion 11 of the solid holder 10. . The holder 10 is made of steel and consists of an outer (N, !I) disk portion 11 and an inner boss portion 12, and the boss portion 12 has a support hole 1 in the center for attaching a grooving grindstone to the grindstone @S.
4 is provided.

The grinding tips 20 consist of nine first grinding tips 21 and three second grinding tips 22, and as shown in FIG.
ItJF grinding tips 22 are arranged between the first grinding tips 21 every 3111i1 along the outer periphery 13 of the holding body 10. As shown in FIG. 1, the first and second grinding tips 21 and 22 are fan-shaped, with grinding wheels 12La and 22a having a width of b% B1 located on the outside of the radius, and grindstones 12La and 22a with a width of b% B1 located on the inside of the radius. The base layer 21b has a width of B2, which is smaller than B1.
, 22b. And the first grinding tip 21
The thickness Ll of the grinding wheel layer 21a is smaller than the thickness L2 of the grinding wheel 122a of the second tlF cutting tip 22, and correspondingly, the thickness of the base layer 21b is larger than the thickness of the base Jm22b. The entire thickness of the second grinding chips 2] and 22 is the same.

As shown in FIG. 3, the grindstone layers 21a and 22a are made by bonding expensive abrasive grains 25a such as diamond abrasive grains or CBN abrasive grains with poor grinding performance using a bonding agent 26 such as resin bond, vitrified bond, or metal bond. The two end surfaces 21c and 22C are used to process the inner surface Wa of the groove of the workpiece W. The base layer 1W 21b, 22b is made of relatively cheap (comparable) particles such as silicon carbide or alumina, and is coated with the grinding wheel layer 21a.
, 22a are bonded using the same bonding agent 26. 1 (stone m 21a + 22 a and base Fi 21b
, 22b are integrally bonded to each other, and the first and second grinding chips 21, 22 are fixed to the outer circumferential surface 1.3 of the disk portion 11 of the holder 10 by adhesive, using the base layers 21b, 22b as buffer layers. ing. Note that the width of the disk 8 (ζ11) is 1-, which is the same as the width B2 of the base layers 21b and 22b.

When in use, the groove machining grindstone attached to the grindstone shaft S is rotated to give cutting feed, and as shown in FIG.
The inner surface Wa of the groove is polished by the end surfaces 21c and 22c of the chinobu 20 which is inserted into the groove of the cutter W and is polished by applying traverse feed.
Grinding is performed so that the width of the grindstone layers 21a and 22a is [31]. Grindstone +=212 by dresser. 22 The outer peripheral surface of a (corrected by 1M, which accounts for the majority of
Even if the thickness t1 of the first grinding wheel layer 21 is reduced, the remaining second
Since the thickness L2 of the low stone layer 22 of the grinding tip 22 is thick, the end face 21c of the thin grindstone layer 21a may cause insufficient grinding.
The remaining portion is ground by the action of the end face 22C of the thick grindstone 122a, and the surface roughness of the groove inner surface Wa is not reduced.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is a front view, FIG. 2 is a sectional view taken along line nn in FIG. 1, and FIG. 3 is a partially enlarged sectional view in FIG. 2. It is. Explanation of symbols

Claims (1)

[Claims] Consisting of a disc-shaped holder and a plurality of fan-shaped grinding tips fixed to its outer periphery, each grinding tip has a grinding wheel layer located radially outward and a lower layer narrower in width than the grinding wheel layer located radially inward. In a grindstone for groove machining, the grinding chips are fixed to the holder through the base layer, and the inner surface of the groove is ground by the end face of each grindstone layer. Consisting of a large number of first grinding chips with a thick layer and a small number of second grinding chips with a thick grinding wheel layer and a thin base layer, the second grinding chips are spaced approximately evenly between the first grinding chips. A grindstone for groove machining characterized by being arranged in.