JPS6311282A - Diamond or cbn wheel - Google Patents

Abstract

PURPOSE:To perform the mounting and demounting of a wheel to a spindle easily as well as to make grinding operation performable at once without entailing any turning deflection as keeping the wheel attached intact, by making a mounting hole slightly eccentric to a wheel peripheral circle working a grinding action. CONSTITUTION:A hole 4 is made eccentric to a wheel periphery 5 as corresponding to a quantity of a clearance 12 between the periphery 5 and a spindle 11. The spindle 11 is fitted in the hole 4 of this wheel 1, thrusting a wedge 14 in the clearance 12, and a wheel alloy 2 is stuck close to the spindle 11 at the opposite side, whereby the wheel 1 is fixed to the spindle 11 without entailing any deflection at the specified position. To remove this wheel 1, if the wedge 14 is pulled out, the wheel 1 comes into a state of being loosened, so that this wheel 1 can be pulled out of the spindle 11 in an easy manner.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a diamond wheel for precision grinding or CBN.
It's about wheels.

[Conventional technology]

In precision grinding using diamond wheels, CBN wheels, etc., it is strongly required that the wheels rotating at high speed on the grinding machine be free from rotational runout. Even if the wheel itself is manufactured with sufficient precision, when it is attached to the spindle of a grinding machine, it is subject to installation errors and runout occurs during one rotation.

In the mounting method by fitting the spindle shaft and the wheel center hole, a gap is required for fitting, and this causes irregular eccentricity within the gap, which causes the wheel to run out at the outer circumference. If the fitting accuracy is extremely high, fitting will become impossible if the temperature of the shaft rises and thermally expands, so it is necessary to create a gap that takes this into account.

Figure 5 shows a commonly used wheel mounting method. In the figure, reference numeral 1 denotes a wheel, which has a structure in which a grindstone layer 3 containing diamond abrasive grains or CBN abrasive grains is provided around the periphery of a metal base 2. The center hole 4 of the base metal 2 is inserted into the part 11 of a predetermined diameter of the spindle shaft 10, but even if the concentricity of the wheel outer circumferential surface 5 and the hole 4 is sufficient, the outer circumference runout 7 due to the above-mentioned gap.
occurs.

For wheels where the wheel thickness, that is, the axial dimension is relatively small compared to the wheel outer diameter, fitting alone will not make the wheel surface perpendicular to the spindle axis, and axial runout (face runout) 8 may occur on the outer periphery. Easy to follow. By abutting the side surface of the wheel base metal 2 against the end surface 16 of the shoulder portion 15 of the spindle shaft 10, squareness is guaranteed and surface runout 8 is prevented. The nut 21 is tightened through the spacer 20 to ensure close contact between the end face 16 of the spindle shaft and the wheel base metal 2, and the wheel is fixed.

Tapered alignment is often adopted as an ideal method for mounting wheels because there is no gap in theory, but due to expansion and contraction due to temperature of the spindle shaft or wheel, the position of the axial mounting of the wheel is not necessarily constant. for.

In the method shown in FIG. 5 for obtaining the perpendicularity of the wheel surface, the close contact between the end surface 16 on the spindle side and the wheel base metal 2 is not guaranteed, and the wheel is fixed at an angle, resulting in surface runout 8.

Additionally, since tapered holes require precision machining, machining costs increase, which affects the wheel cost.

Although the case where the wheel is directly attached to the spindle shaft has been described above, a method of attaching the wheel via a jig, commonly called a flange, is also commonly used. 6th
FIG. 30 shows a flange, and the mechanism for attaching the wheel 2 to this flange is exactly the same as that shown in FIG. 5. Since the flange 30 is attached to the spindle shaft 1'O' with taper alignment as shown in the figure, there is no problem with the gap, and the necessary parts such as the shaft part 11' that receives the wheel and the end face 16' are made with sufficient precision without runout. Manufactured. However, there remains a gap problem when fitting the wheel.

[Problem that the invention seeks to solve]

As mentioned above, even if the wheel itself has sufficient accuracy, rotational runout is unavoidable when the wheel is attached to a spindle. In order to eliminate rotational runout, it is said that ``on-machine truing'' is a good way to correct the working surface of the wheel by attaching the wheel to the spindle of the grinding machine being used and rotating it.

Diamond wheels and CBN wheels are worn out,
Once trued, it maintains its accuracy for a considerable period of time, but on the other hand, it is not always easy to perform correction work that wears it down.

The grinding machine requires a special mechanism for this purpose, and the truing operation, which takes a long time, is stopped, which impairs work efficiency. Additionally, in automatic grinding systems, it may be difficult to incorporate truing.

Another method is to remove the flange from the grinder, take it to a wheel manufacturing factory, attach the wheel to it, and finish the outer periphery to eliminate runout. This type of finishing is always done as the final step in precision wheel manufacturing, and manufacturing plants have the equipment and technology for this purpose.

If this process is performed while the wheel is attached to the flange, and the wheel is subsequently treated as an integral piece with a flange, it will remain stable even if it is repeatedly attached to and detached from the grinder, and there is no need for on-machine truing.

However, one flange is monopolized for each wheel,
In addition, when manufacturing a new wheel or modifying a wheel, the flanges are sent to a wheel manufacturing factory, so a large number of flanges must be kept in stock.

In addition, wheel manufacturing factories use precision tapers with the same taper specifications as the spindle shaft in order to rotatably hold flanges, but since the taper specifications vary depending on the model of grinding machine, they must have a large number of precision tapers. Must be.

Since the grindstone layer 3 of the electrodeposited wheel is extremely thin, there is no room for modification, and in principle, neither on-machine truing nor finishing at a wheel manufacturing factory is possible. Therefore, the problem of rotational runout is particularly serious.

[Means for solving problems]

The present invention can be applied directly to the spindle or via a flange.
The purpose of the present invention is to provide a diamond or CBN wheel that, when installed, has both outer circumferential runout and surface runout within permissible ranges, allows immediate precision grinding work, and does not require on-machine truing.

It is also an object of the present invention to provide a mounting method in which the work of mounting and dismounting the wheel is simple and easy and does not take an hour.

Furthermore, it is an object of the present invention to eliminate the need for difficult and costly machining processes such as taper alignment in manufacturing the wheel.

In order to achieve the above object, the wheel of the present invention avoids the tapered fitting method and adopts a straight hole fitting to a straight shaft.

A wheel hole with a diameter that allows for a gap for fitting is made eccentric in accordance with the amount of gap, and at the same time, the eccentricity of the wheel itself is eliminated using a wedge or the like to remove an undefined element due to the gap.

[For production]

FIG. 1 is a schematic diagram explaining the present invention in detail, and FIG. 2 is a longitudinal sectional view of one embodiment. Hereinafter, up to FIG. 6, the same parts are given the same numbers.

In FIG. 1, there is a gap 12 between the hole 4 of the wheel 1 and the spindle shaft 11. When the wedge 14 is pushed in, the wheel base metal 2 comes into close contact with the shaft 11 on the opposite side 15, and the position of the wheel 1 with respect to the shaft 11 is fixed, thereby eliminating the undefined element caused by the gap 12.

The wedge 14 engages with a keyway 13 provided in the shaft 11. As can be seen in FIG. 2, the bottom of the groove 1.3 is sloped to receive the wedge 14.

As seen in FIG. 1, the hole 4 is eccentric with respect to the wheel outer periphery 5, so during installation, the direction of eccentricity 6 should be aligned with the position of the wedge.

Theoretical calculations and actual measurements have proven that this alignment can be approximate and does not require precision. However, the gap 12 and therefore the amount of eccentricity of the wheel are exaggerated in Figure 1, and in reality, the appropriate value is less than O, lna, so the eccentricity cannot be recognized visually, so index 6 is necessary. .

As mentioned above, as the final step in manufacturing precision wheels, the wheel is attached directly or via a flange to a taper with the same specifications as the spindle shaft of the grinding machine used after shipping, and the outer circumference of the wheel is machined to remove runout while rotating. . Taper key groove 13
By attaching it in a predetermined manner to the taper or flange provided with the wheel, the desired wheel can be finished in a manner completely equivalent to the conventional process described above.

The eccentricity of hole 4 is a result of this finishing process,
There is no need to be conscious of eccentricity throughout the entire production process. Further, although the gap 12, that is, the eccentricity is minute as described above, its value does not need to be accurate. This is because, in principle, this method provides a wheel with no runout, regardless of the value of the gap or eccentricity.

〔Example〕

It is clear that the wheel of the invention is equally applicable both directly to the spindle and via a flange.

The above manufacturing method is applied to metal bond, resin bond, and Vitribond wheels. To manufacture an electrodeposited wheel, the periphery of the base metal may be processed using the method described above, and diamond or CBN abrasive grains may be electrodeposited thereon.60-Taly dresser is also a tool that requires strict rotational accuracy, and the present invention The eccentric structure of is effectively applied. The rotary dresser is structurally almost the same as a metal bonded diamond wheel and is therefore included in the present invention.

In FIGS. 1 to 3, the keyway 13 into which the wedge 14 is inserted is provided on the shaft 11, but it can also be provided on the wheel base 2, and in this case, the positioning index 6 is not necessary. However, keyway machining is required for each wheel. axis 1
Since an unspecified number of wheels are replaced and attached to each flange, it is more economical to provide the keyway on the spindle shaft or flange because the amount of machining is reduced.

To determine the position of the wheel 1 with respect to the wedge 14, an index 6 is stamped on the base metal 2 as shown in FIG.

Alternatively, as shown in FIG. 2, there is a method in which a pin hole 9 is provided in the base metal 2 and the pin hole 9 is engaged with a pin 17 implanted in the end face 16 on the spindle side, which reduces the burden on the operator during installation.

To remove the wheel, remove nut 21 and then
If you remove the wheel, the wheel will loosely fit onto the shaft and can be easily pulled out. To remove the wedge, if a wedge 14' having a protrusion 18 at the rear as shown in FIG. 3 is used, it can be easily removed using a lever 22. Spacer 20' has pattern 1
4' protrusion 18 and a recessed part 2 that accommodates the tip of the lever 22
3 will be provided.

The effect of the wedges 14, 14' is to widen the gap and bring the inner wall of the wheel bore 4 into close contact with the axle 11 on the opposite side 15. There are also non-mimetic methods for this type of effect. For example, FIG. 4 shows a well-known configuration using steel balls. A steel ball 41 is loosely fitted into a recess 4o provided on the surface of the shaft 11 into which the wheel 1 is fitted. The purpose is achieved by tightening the screw 42 from the end face 19 and pushing the steel ball 41 outward by the conical part 43 at the tip.

〔effect〕

In precision grinding using diamond wheels, CBN wheels, etc., rotational runout of the wheels always poses a problem. The present invention solves this problem, and once a received wheel is installed, grinding work can be performed directly without rotational runout. It does not require on-machine truing, which requires technical skill and is inefficient, and it is easy to install and remove, so work efficiency is greatly improved. Also, since wheel manufacturing does not require special equipment or work, the wheel price is low.

Therefore, tool consumption costs do not increase.

In the case of the flange method, the wheel is manufactured by attaching it to the processing flange and finishing processing is performed, so there is no need to bring in the actual flange. Therefore, it is not necessary to have a large number of flanges in actual use; in the extreme, one flange per grinding machine is sufficient.Flanges for processing require precision that matches the dimensional standards of the wheel, but Since it is not intended to be mounted, no tapered holes are required. The manufacturing factory only needs to have a processing flange that corresponds to the standard of the wheel hole.
The burden on the manufacturer is lighter than having to own a large number of tapers corresponding to different types of grinding machines, and this has a favorable effect on wheel prices.

The above will greatly contribute to the machining industry.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram explaining the principle of a diamond or CBN wheel according to the present invention, Fig. 2 is a vertical cross-sectional view showing an embodiment of the present invention, and Fig. 3 is a diamond or CBN wheel driven into the gap between the shaft and the hole. FIG. 4 is a cross-sectional view showing an example in which a wheel is fixed in a hole using a steel ball, and FIGS. 5 and 6 are cross-sectional views showing a conventional wheel mounting structure. jIi diagram, 4th @ σ diagram

Claims (1)

[Claims] A diamond or CBN wheel characterized by a mounting hole that is slightly eccentric with respect to the outer circumferential circle that performs the grinding action.