JP2828377B2 - Grinding method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for grinding a workpiece such as a mold, and more particularly to a resin-based grinding method which supports fine abrasive grains with a resin and has continuous pores between the abrasive grains. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding method capable of performing high-precision finish grinding using a permeable grindstone, and a grinding apparatus that performs the grinding method.

[0002]

2. Description of the Related Art Conventionally, grinding has been used for finishing work of a work after cutting or for shaving a work surface hardened by surface treatment, etc., from a work material, a surface hardness of a machined surface, and a rough cutting stage. This is achieved by selecting and using an appropriate type of grindstone in accordance with various processing conditions such as a difference in the amount of grinding according to the processing stage in the superfinishing stage. Examples of such grinding wheels include a resin-based grindstone in which a resin bond material (resin bond material) is used as an abrasive grain support, a vitrified grindstone in which an abrasive grain support material is crystallized by sintering, a casting material, and the like. And a metal-based grindstone using the above metal as an abrasive support. In particular, in the vitrified whetstone, there is a gap between the abrasive grains by supporting coarse abrasive grains with a crystal support,
There is also one that has air permeability and water permeability, and removes and cools grinding dust in a grinding portion by ventilation and water flow.

[0003]

However, breathability,
Even in the case of a grindstone having water permeability, in the case of a conventional vitrified grindstone, since the abrasive grain size is coarse, the roughness on the ground surface of the work, that is, the surface roughness is inevitably large, There is a drawback that it cannot be used for finish grinding of a mold or the like. In particular, when the grinding fluid is allowed to flow through the grindstone, dust in the grinding fluid is filtered and deposited in the gaps between the abrasive grains, causing clogging. There is also a problem that it is difficult to perform the grinding process. Moreover, in the case of vitrified grindstones, the hardness of the crystallized abrasive support itself is large, and in the case of a relatively soft work, the generation of scratches by the crystal support on the ground surface cannot be avoided. There are drawbacks that cannot be used in superfinishing applications.

On the other hand, some resin-based grindstones have a fine abrasive particle diameter and are softer than a vitrified support, but a resin-based grindstone having air permeability inside the grindstone has not yet been provided. However, recently, there is a tendency to develop and provide a permeable grindstone having continuous pores between the abrasive grains while supporting fine abrasive grains such as diamond with a resin bond material.

Accordingly, an object of the present invention is to provide a fine finish ground surface by supporting such fine abrasive grains with a resin bond material and using a gas-permeable grindstone having continuous pores between the abrasive grains. An object of the present invention is to provide a grinding method capable of stably performing the obtained super-finishing grinding for a long time and a grinding apparatus used for performing the grinding method. Another object of the present invention is applicable to super finishing processing after finishing cutting by end mill cutting or hale cutting, etc., and therefore, a fine surface roughness by super finishing the working surface such as a die. It is intended to provide a grinding method and a device capable of performing a grinding process on a mold surface.

[0006]

SUMMARY OF THE INVENTION In view of the above objects,
The present invention recently uses a grindstone having air permeability by having continuous pores between fine abrasive grains being developed, and a grinding section by relative movement between the grindstone and a work to be processed. While supplying the grinding fluid to the grinding point of the above, the gas and liquid are mixed in the grinding section by ejecting the pressurized gas which is ejected to the same grinding section through the pores of the grinding stone,
Thus, a grinding method and a grinding apparatus configured to promote the removal of the processing chips by the grinding fluid and the cooling action are configured.

That is, according to the present invention, there is provided a grinding method for performing processing by moving a permeable grinding wheel having continuous pores between abrasive grains relative to a workpiece to be processed, wherein A grinding fluid is supplied to a grinding portion where contact between the workpiece and the workpiece is made, and a gas pressurized in the pores of the grinding wheel is sent and ejected toward the grinding portion, and the pressurized gas is discharged. And a grinding fluid are mixed in the grinding section to perform a grinding process.

Further, according to the present invention, a permeable grinding wheel having continuous pores between abrasive grains, and a lapping tool for performing a grinding process by moving the permeable grinding wheel relative to a workpiece to be processed. Moving means, a grinding fluid supply means for supplying a grinding fluid to a grinding portion with the permeable grindstone, and a pore of the permeable grindstone to mix a pressurized gas into the grinding fluid flow in the grinding portion. There is provided a grinding apparatus configured to include a pressurized gas supply unit for supplying a pressurized gas ejected to the grinding section through the grinding section.

[0009]

According to the above construction, the jet flow of the pressurized gas passing through the pores of the grindstone is mixed with the grinding fluid supplied to the grinding portion in the grinding portion to urge the flow of the grinding fluid. As a result, the action of removing grinding dust and the cooling action by the grinding fluid flow are promoted.
Therefore, for a long time without causing clogging,
Since a stable grinding operation is continued, the grinding of a work having a fine finish grinding surface can be achieved by the fine abrasive grains. Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings.

[0010]

FIG. 1 is an enlarged cross-sectional view of a grinding wheel section for explaining a basic configuration and operation of a grinding method according to the present invention. FIG. FIG. 3 is a cross-sectional view of a grinding portion showing an embodiment applied to surface grinding of a workpiece by using the grinding method. FIG. FIG. 4 is a cross-sectional view of a ground portion, and FIG. 4 is a cross-sectional view of a ground portion showing an embodiment in which the grinding method according to the present invention is applied to surface grinding of a work using a non-rotating grindstone. It is sectional drawing by line 5-5.

In the enlarged cross-sectional view of FIG. 1, an air-permeable grindstone 10 used for carrying out the grinding method of the present invention is made of known abrasive particles such as diamond particles, and has abrasive grains 11 having a relatively small particle diameter. For example, it is bonded and supported by a resin-based bond 12 such as a melamine resin, and a gap-like structure that is continuous from one end of the grindstone 10 to the grinding action portion side between the structures inside the grindstone composed of the abrasive grains 11 and the bond 12. Pores are formed, and the grindstone 10 is provided with air permeability (and therefore also has water permeability) by these pores. Therefore, when a pressurized gas such as pressurized air is supplied from one end side of the grindstone 10, the pressurized gas becomes Through the pores as indicated by the dotted line, and
0, the structure is such that it is ejected toward a contact portion between the workpiece W to be processed and the grindstone 10, that is, a grinding portion GR. In addition, the grindstone 10 is coated with a resin material or the like as necessary in a peripheral region so that the supplied pressurized gas is ejected to a desired grinding portion GR after passing through the pores of the grindstone 10, The illustrated example shows that the coating layer 13 is provided in the side surface region.

When the work surface of the work W is ground by using such a permeable grindstone 10, a relative feed movement is provided between the work W and the grindstone 10, and the rough work is performed. It should be understood that the provision of an appropriate cut in accordance with the processing stage leading to the super-finishing is no different from the conventional grinding method. The relative feed movement between the grindstone 10 and the work W may be performed when the grindstone 10 is mounted on a grindstone head (not shown) of a grinding machine or when the work W
When a work table (not shown) equipped with is operated in a feed operation, when both movements are combined, etc., various processing conditions such as the work material and shape or whether the work surface of the work W is a milling processing surface or a hail processing surface. Needless to say, it is appropriately selected according to the situation. In FIG. 1, the work W and the grindstone 1 are temporarily
The direction of movement relative to zero is indicated by arrow F.

On the other hand, during the grinding operation process of the grindstone 10, a grinding liquid is supplied from outside the grindstone 10 to the grinding portion GR to remove grinding debris and cool the grinding portion GR.
It is necessary that the supply direction of the grinding fluid is appropriately selected so as to be surely supplied to the processing point of the grinding portion GR.
It is well known to those skilled in the art. In the illustrated example, the work W
3 shows a case where the grinding fluid is supplied from the right end side of the workpiece W and discharged to the left end side of the work W through the grinding portion GR.

According to the present invention, the grinding fluid is supplied as described above and the predetermined pressure is passed through the pores of the internal structure of the grindstone 10 during the grinding of the work surface of the work W by the grindstone 10. Is supplied.
That is, for example, pressure air is introduced from one end of the grindstone 10 into the internal structure through a pressure air circuit passing through an appropriate filter element from a pressure air source, and supplied so as to be jetted to the grinding portion GR. As a result, the pressurized air jetted to the grinding portion GR mixes and flows while applying a pressing action to the flow of the grinding fluid flowing through the grinding portion GR, thereby promoting the discharge of the grinding fluid. Therefore, the action of flushing and removing grinding chips by the grinding fluid is further doubled, and at the same time, the cooling action is promoted by the high speed of the fluid flow. Moreover, the grinding fluid is rapidly discharged from the grinding portion GR while flushing the grinding chips, and the pressurized air flows from the inside of the grindstone 10 into the grinding portion GR.
The grinding dust removed by the grinding fluid is reliably prevented from adhering to the grinding portion of the grindstone 10 and from penetrating into the inside structure of the grindstone. Therefore, clogging is reliably prevented from occurring in the grinding portion of the grindstone 10 facing the surface to be machined during the grinding process, so that the grinding process can be stably continued for a long time. .

FIG. 2 shows a first embodiment to which the grinding method according to the present invention described with reference to FIG. 1 is applied. The air-permeable grindstone 10 is formed as a cup-shaped grindstone 20. It is held by a grindstone support 22 of the grindstone head and a grindstone holder 24 locked to the grindstone support 22 by a screw engaging portion 26. The above cup-shaped whetstone 2
Numeral 0 is provided so that the work surface of the work W is ground by using the bottom surface as a grinding portion, and the work W is rotated in the direction of arrow A together with the grindstone support 22 of the grindstone head.
Is driven by moving means (not shown) along the surface to be processed to perform a relative movement, thereby giving a grinding operation to the surface to be processed.

Here, the pressurized gas supply means 3
A pressurized gas such as pressurized air sent from line 0 through a pipe passage 32 is supplied through gas passages 34 and 36 provided in the grindstone support 22. It passes through the pores formed between the grains and is ejected from the grinding portion of the grindstone 20 to the grinding portion GR that comes into contact with the workpiece W. The cylindrical outer surface 20a of the grindstone 20 is in close contact with the cylindrical inner surface 22a of the grindstone support 22, and the cylindrical inner surface 20b of the grindstone 20 is covered with the coating layer 20C. It is formed so as not to be ejected from the cylindrical inner surface 20b.

On the other hand, from the grinding fluid supply means 40 to the fluid conduit 42
Through the liquid passage 44 of the grindstone support 22 and the grindstone holder 24
The grinding fluid is supplied to the grinding portion GR in the space formed in the lower bottom portion of the grindstone 20 via the fluid passage 46 provided in the grinding wheel 20, and the grinding fluid is supplied by the annular grinding portion of the cup-shaped grindstone 20. It flows and is discharged outside through the grinding point. According to the present invention, when the grinding fluid flow passes through the grinding point, it is mixed with the above-mentioned pressurized gas ejected from the inside of the grindstone 20 to increase the speed, and the grinding dust ground from the work W While being rapidly removed to the outside while flushing, the grinding fluid, which has increased the heat generated during the grinding operation, effectively removes the heat and cools the work surface of the work W. Therefore, the grinding action portion of the grindstone 20 is always maintained as a normal grinding action portion without clogging, and a stable grinding action is continued for a long time.

Here, the permeable grindstone 2 used in the present invention.
0 is a fine abrasive grain having a small abrasive grain diameter, and having a structure bonded at a high density with a resin bond softer than the crystallization support of the vitrified grindstone, and as described above, it is stable for a long time. The work surface of the work W is finished as an extremely dense ground surface, and is empirically cut with a surface roughness of 2 to 5 μm Rmax. It is possible to perform a grinding process for finishing the surface to a dense surface having a surface roughness of about 0.05 μmRmax.

The above-described first embodiment is an embodiment in which a cutting plane or the like of a work W is ground by a rotating grindstone 20. The second embodiment shown in FIG. An example in which a vertical side surface of a work W is ground is shown. In this embodiment, the air-permeable grindstone 50 has a hollow cylindrical shape, and is attached to a small-diameter grindstone holding portion 53 formed at the lower end of a cylindrical grindstone support tool 52.
Are supported and fixed from the lower end side. The presser 54 is locked to the grindstone support 52 by a screw engaging portion 56 in the same manner as the presser 24 of the first embodiment described above, and the flange 58 of the presser 54 and the small-diameter grindstone holding end. The grindstone 50 is sandwiched between the upper end of the portion 53 and the seat.

The air-permeable grindstone 5 used in this embodiment
0 is the relative movement in the vertical direction along the vertical plate-like side surface and the cylindrical wall surface of the work W while rotating (arrow R) with the grinding wheel support 52 using the outer cylindrical surface 50a as a grinding action portion. Grinding is applied to the side and wall surfaces of the work. Here, during the grinding process using the grindstone 50, a pressurized gas, for example, pressurized air supplied from the pressurized gas supply means 30 through the pipe line 32 is supplied to the grindstone support 52.
The grinding wheel 5 passes through the vertical passage 34 and the annular passage 36 formed in
At this time, the pressurized air passes through the pores in the internal structure of the air-permeable grindstone 50 and is jetted from the grindstone outer cylinder surface forming the grinding action portion. Here, the upper and lower surfaces of the grindstone 50 are the flange portions 5 of the grindstone support tool 52 and the holding tool 54.
8, the pressurized air is intensively blown out of the grinding portion of the outer cylinder surface 50a of the grindstone 50 to the outside.

On the other hand, the grinding fluid is supplied directly from the grinding fluid supply means 40 to the machining point in the grinding portion GR where the grinding portion of the outer cylindrical surface 50a of the grinding wheel 50 contacts the work surface of the workpiece W via the pipe line 42. Are supplied. At this time, the grinding fluid is pressurized and accelerated by a pressurized gas such as pressurized air ejected from the grinding portion of the grindstone 50, so that the grinding portion GR is quickly squeezed similarly to the above-described embodiment. This removes and removes grinding dust from the surface, and cools the surface of the work W and the surface of the grindstone in the grinding portion GR. As a result,
Also in the present embodiment, the grinding action portion of the outer cylindrical surface 50a of the grindstone 50 can constantly apply a normal grinding process to the workpiece surface without being clogged by grinding dust. It is. Therefore, the work surface of the work W can be ground to a high-precision super finish ground surface.

In the grinding method according to the present embodiment, a work surface cut in advance by a known machining center or milling machine can be subjected to finish grinding to form a fine super-finished surface. Therefore, in a mold or the like,
Finish grinding of the vertical wall surface region rising from the bottom surface can be appropriately achieved. In the first and second embodiments described above, a resin-based grindstone in which air-permeable fine abrasive grains are bonded and supported at high density with a resin bond is used as a grindstone support 22.
Or the embodiment in which the grinding is performed by giving a relative movement between the workpiece and the surface to be processed while being rotated together with 52.
For example, in the case of performing a finishing process of a work surface to be cut by a hale bite by a grinding process, the grindstone is repeatedly moved relative to the work surface in a non-rotating state to perform the grinding process. It is also possible to do so.

FIGS. 4 and 5 show an embodiment in which the surface to be processed is ground by such a non-rotating grindstone. 4 and 5, the square bar-shaped grindstone 60 is made of a breathable resin-based grindstone as in the above two embodiments, and the upper end is mounted in the square-hole-shaped grindstone holding hole 63 of the grindstone support 62. ing. The whetstone 60 has a set screw 64
As shown in FIG. 5, three peripheral wall surfaces of the peripheral wall of the grinding wheel 4 facing the wall surface of the grinding wheel holding hole 63 are covered with a coating layer 60b, and the other peripheral wall is coated with a coating layer. When the pressurized gas, for example, pressurized air, for example, is supplied from the pressurized gas supply means 30 from above the grindstone support 62 through the pipe passage 32 and the passage 34 by not providing the grindstone support 62, the pressurized air becomes After passing through the pores, it is ejected from the peripheral wall of the grindstone without the coating layer 60b and the grinding action part for grinding the work surface.

On the other hand, a liquid port 65 opened in the inner wall surface of the grindstone holding hole 63 facing the peripheral wall of the grindstone 60 where the coating layer 60b is not provided is provided with a liquid passage 66 formed in the grindstone support 62 and an external pipe. Grinding fluid supply means 4 via passage 42
0 and the grinding fluid supply means 4 during the grinding process.
The grinding fluid is continuously supplied from 0 to the machining point in the grinding section GR where the grindstone 60 and the workpiece surface come into contact with each other through the liquid port 65.

As a result, in the grinding portion GR, the grinding fluid mixes with the pressure air ejected through the pores of the internal structure of the grindstone 60, and is urged and accelerated by the same pressure air to increase the flow rate. Grinding debris generated at a point is quickly conveyed and removed, and the grinding heat generated at a grinding point on a workpiece surface is removed and cooled. That is, the action of removing grinding dust and the cooling action by the grinding fluid are promoted. Moreover, as described above, since the occurrence of clogging is prevented at the grinding action portion of the grindstone 60, the grinding action of the grindstone 60 having high-density fine abrasive grains is stabilized during the grinding of the work W. Therefore, it is possible to finish-process the work surface of the work W, in particular, the work surface after the hale cutting, into a dense ground surface. Of course,
The present embodiment is not limited to the finish grinding of the hale cut surface by the hale cutting tool, and it is needless to say that the present embodiment can be applied to the use of performing the finish grinding on the milled surface.

The fluid from the pressurized gas supply means 30 or the grinding fluid supply means 40 may be introduced into the grindstone by using a known spindle through coolant apparatus or tool through coolant apparatus.

[0027]

As can be understood from the description of the various embodiments described above, according to the present invention, there is provided a structure in which fine abrasive grains such as diamond, which have been recently developed, are bonded with a resin-based bond. Then, using a grindstone with air permeability by having continuous pores between the abrasive grains, and, while supplying the grinding fluid to the grinding point of the grinding portion by the relative movement of the grindstone and the workpiece, the grinding wheel By ejecting the gas pressurized to the grinding part through the pores, the gas-liquid is mixed in the grinding part, thereby promoting the removal of the processing chips and the cooling action by the grinding liquid, and As a grinding method and apparatus for preventing clogging of the grinding wheel are provided,
A constant grinding action can always be imparted to the entire surface of the work surface of the work, and a dense ground surface with extremely small surface roughness can be obtained. As a result, the work surface of the workpiece can be used for finishing to a high-precision finished surface.

Further, according to the present invention, clogging of the grinding portion of the grinding wheel can be reliably prevented, so that a long life of the grinding wheel itself can be guaranteed.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a grinding wheel section for explaining a basic configuration and operation of a grinding method according to the present invention.

FIG. 2 is a sectional view of a grinding portion showing an embodiment in which the grinding method according to the present invention is applied to surface grinding of a work using a rotary grindstone.

FIG. 3 is a cross-sectional view of a grinding portion showing an embodiment in which the grinding method according to the present invention is applied to grinding of a side surface of a work using a rotating grindstone.

FIG. 4 is a cross-sectional view of a grinding portion showing an embodiment in which the grinding method according to the present invention is applied to surface grinding of a work using a non-rotating grindstone.

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Whetstone 11 ... Abrasive grain 12 ... Bond 13 ... Coating layer 20 ... Whetstone 22 ... Whetstone support 24 ... Holder 30 ... Pressurized gas supply means 40 ... Grinding fluid supply means 50 ... Whetstone 52 ... Whetstone support 54 ... Hold Tool 60: Grinding stone 62: Grinding stone support W: Work GR: Grinding part

Claims (2)

(57) [Claims] 1. A grinding method for performing processing by moving a permeable grinding wheel having continuous pores between abrasive grains relative to a workpiece to be processed, wherein the permeable grinding wheel and the workpiece are The grinding fluid is supplied to the grinding portion where contact occurs between the grinding wheel and the gas pressurized in the pores of the grinding wheel is sent toward the grinding portion, and the gas is blown out. Grinding is performed by mixing the fluids in the grinding portion. 2. A permeable grinding wheel having continuous pores between abrasive grains, a relative moving means for performing a grinding process by relatively moving the permeable grinding wheel with respect to a workpiece to be processed, and A grinding fluid supply means for supplying a grinding fluid to a grinding portion by a grindstone; and, in order to mix a pressurized gas into a liquid flow of the grinding fluid in the grinding portion, through a pore of the permeable grindstone to the grinding portion. Pressurized gas supply means for supplying a pressurized gas to be ejected,
A grinding apparatus characterized by comprising: