WO2019131846A1

WO2019131846A1 - Grinding method and grinding device

Info

Publication number: WO2019131846A1
Application number: PCT/JP2018/048065
Authority: WO
Inventors: 主税森合
Original assignee: 株式会社トクピ製作所
Priority date: 2017-12-31
Filing date: 2018-12-27
Publication date: 2019-07-04
Also published as: JPWO2019131846A1

Abstract

The present invention performs grinding wherein adhesion of machining dust to the abrasive grain surface of a diamond grindstone is prevented as much as possible. A grinding device (1) is for grinding a workpiece (W) made of a superalloy on the grinding surface (2ba) of a diamond grindstone (2b) of a grinding wheel (2) while rotating the grinding wheel (2). This grinding device is provided with an abrasion liquid spraying means (3) for spraying, on the grinding surface (2ba), a high-pressure abrasion liquid through a nozzle (3a) from a direction orthogonal to the grinding surface (2ba) so as to wash off grinding powder. The abrasion liquid spraying means (3) is disposed at an abrasion liquid spraying position (P1) different from a workpiece grinding position (P2) for grinding the workpiece (W). A nozzle (3a) of the abrasion liquid spraying means (3) is configured to oscillate.

Description

Polishing method and polishing apparatus

The present invention relates to a polishing method and a polishing apparatus using a hard grindstone such as a diamond grindstone or a CBN grindstone.

The diamond grindstone is obtained by bonding diamond abrasive grains with a binder, and is a hard grindstone as compared to a conventional grindstone using aluminum oxide or the like. Further, as a hard grindstone, there is a CBN grindstone. The CBN grinding wheel is a hard grinding wheel using cubic Boron Nitride which is a compound consisting of boron and nitrogen.

The diamond grindstone and the CBN grindstone described above are widely used from a conventional work to a work made of a super alloy such as, for example, Inconel (registered trademark). In addition, when grinding a superalloy work or the like, clogging occurs in the grindstone. Conventionally, when such clogging occurs, in order to restore the polishing performance, one layer of the clogged polishing surface (abrasive grain surface) is scraped off by a diamond dresser or the like.

Since such a whetstone is expensive as compared with the conventional whetstone, there is a demand to be able to polish for as long as possible without cutting off with a dresser as much as possible.

By the way, in order to prevent clogging of the polishing surface, the workpiece is polished while the liquid exudes from the inside of the rotating polishing tool during polishing and / or the liquid is sprayed onto the polishing tool from the outside of the polishing tool. (See, for example, Patent Document 1).

JP 2007-118130 A

For example, when polishing a workpiece made of a super alloy such as Inconel (registered trademark) with a diamond grinding wheel or the like as described above, the abrasive powder causing the clogging firmly intrudes between the diamond abrasive grains and exudes the liquid. It is difficult to suppress clogging only by polishing the work while spraying and / or spraying liquid onto the polishing tool from the outside of the polishing tool.

The present invention provides a polishing method and a polishing apparatus capable of suppressing clogging of a polishing surface such as a diamond grindstone.

The polishing method according to one aspect of the present invention is a polishing method for polishing a workpiece made of a super alloy while rotating a diamond grinding wheel formed by bonding diamond abrasive grains with a binder, and the diamond for polishing the workpiece It is characterized in that the work is polished while spraying a high-pressure grinding fluid while changing a part to be sprayed on the polishing surface of the grindstone.

In this way, when polishing, the grinding fluid is sprayed with a high pressure to the polishing surface (abrasive grain surface) while changing the spray site, so that the abrasive powder that causes clogging is washed away, and dressing The polishing operation can be continued for a long time without performing Thus, the number of dressings can be reduced. In particular, not only spraying with high pressure, but also spraying while changing the site to be sprayed, washing can be performed evenly. Here, the grinding fluid is mainly used for the purpose of suppressing clogging removal and clogging of the abrasive grain surface of the grinding stone, but also acts as a coolant for cooling the abrasive grain surface. For the grinding fluid, purified water is used as an example.

In particular, in the case of the diamond grinding wheel using the above-mentioned diamond abrasive, when dressing is performed, it is necessary to remove a layer in which many expensive diamond abrasives are present, which is very costly. In addition, since the diamond abrasive grains have extremely high hardness, it is very difficult to grind the surface of the grinding wheel with a maintenance grinding wheel or the like to grind the surface of the grinding wheel and restore the polishing performance like a normal grinding wheel. there were. This is because the diamond abrasive is harder than the maintenance grindstone. Therefore, while the maintenance of the diamond grinding wheel was very difficult, the surface of the diamond grinding wheel can be recovered without grinding the diamond abrasive grains by using the above-described present invention, which is very revolutionary. .

Further, in this polishing method, the diamond grinding stone is separated at a high pressure of 8 MPa or more and 50 MPa or less at a position different from the position where the grinding fluid grinds the workpiece, 1 mm to 20 mm away from the direction orthogonal to the grinding surface. It is desirable to spray on the polished surface.

In this way, clogging can be effectively suppressed without impairing the workability of the polishing operation. Here, it is more effective that the spouting position of the grinding fluid is approximately 5 mm away from the direction orthogonal to the polishing surface.

Further, in this polishing method, spraying of the grinding fluid is linear injection with an injection angle of 0 degrees or injection with an injection angle of 15 degrees or less. In this way, high pressure spraying of the grinding fluid is possible. Moreover, while the pressure becomes higher when the injection angle is 0 degree, the spray area to the abrasive surface becomes larger by adding the injection angle. In addition, as for the separation distance from a grinding | polishing surface, when providing an injection angle, 5 mm or less is preferable.

Moreover, it is preferable that the pressure sprayed on the grinding | polishing surface of the said diamond grindstone is a high voltage | pressure of 10-15 Mpa as this grinding | polishing method. This is more desirable from the viewpoint of workability and cost of the polishing operation.

Further, in this polishing method, the diamond grinding wheel has an annular polishing surface having a fixed length in the radial direction, and a portion to which the grinding fluid is sprayed to the polishing surface is an inner diameter side portion in the radial direction. It is desirable to rock between the outer diameter side portion.

In this way, high-pressure grinding fluid can be sprayed over the abraded portion of the diamond wheel where the workpiece is abraded. The portion to which the grinding fluid is sprayed to the polishing surface may be reciprocated in the radial direction between the inner diameter side portion and the outer diameter side portion. In this way, when the work is large, high-pressure grinding fluid can be sprayed on the entire polishing surface regardless of the inner diameter side portion and the outer diameter side portion. If the size of the work is small, the portion to which the grinding fluid is sprayed may be fixed.

Further, in this polishing method, the work is polished while supplying the coolant to the polishing surface separately from the high-pressure grinding fluid sprayed onto the polishing surface of the diamond grindstone. In this way, grinding can be performed while cooling the grindstone and the work, and cooling liquid intervenes on the ground surface of the grindstone and the work to enable smooth grinding.

In this polishing method, purified water is used as the high-pressure grinding fluid, and purified water after being used as the grinding fluid is used as the coolant. In this way, by using purified water without using a liquid with impurities such as ground water and tap water in the high-pressure grinding fluid, it is possible to suppress the existence of foreign matter in the pump, the nozzle, etc. Life span is extended. On the other hand, since the coolant is used without passing through a high pressure nozzle or the like, the used grinding fluid may be used. In addition, after filtering the used grinding fluid, you may use as a cooling fluid.

In addition, this polishing method is carbonized by combining a CBN whetstone, or an aluminous-based whetstone formed by bonding aluminous-based abrasive grains with a binder instead of the diamond whetstone, or a silicon carbide-based abrading grain with a binder. The present invention is also applicable to the case of using a silicon-based grindstone.

A polishing apparatus according to one aspect of the present invention is a polishing apparatus for polishing a workpiece made of a super alloy while rotating a diamond grinding wheel formed by bonding diamond abrasive grains with a binder, and the above-mentioned diamond is used during polishing. Grinding fluid spraying means for spraying grinding fluid at high pressure from a direction perpendicular to the polishing surface on the grinding surface of the grinding wheel through a nozzle is provided, and the grinding fluid spraying means is a nozzle that changes the spraying location of the grinding fluid by moving the nozzle. It is characterized by having a moving means.

In this way, the nozzle that sprays the high-pressure grinding fluid sprays on the polishing surface while changing the spraying site, so that the polishing powder that tends to adhere to the polishing surface is washed away evenly, and the polishing operation is performed for a long period of time Can continue.

Further, in this polishing apparatus, the diamond grinding wheel has an annular polishing surface having a fixed length in the radial direction, and the nozzle moving means performs the polishing at a position different from the polishing position for polishing the workpiece. Preferably, the nozzle is swung between the inner diameter side and the outer diameter side in the radial direction with respect to the surface.

In this way, high-pressure grinding fluid can be sprayed over the abraded portion of the diamond wheel where the workpiece is abraded, and efficient polishing can be realized. The portion to which the grinding fluid is sprayed to the polishing surface may be configured to be reciprocally movable between the inner diameter side portion and the outer diameter side portion in the radial direction. In this way, when the work is large, high-pressure grinding fluid can be sprayed on the entire polishing surface regardless of the inner diameter side portion and the outer diameter side portion. If the size of the work is small, the portion to which the grinding fluid is sprayed may be fixed.

Further, in the polishing apparatus, the grinding fluid spraying means can spray the grinding fluid at a high pressure of 8 MPa or more and 50 MPa or less. In this way, clogging can be significantly suppressed as compared with the conventional polishing apparatus.

Further, in this polishing apparatus, the nozzle is a nozzle in which the spray of the grinding fluid is a linear injection with an injection angle of 0 degrees or an injection with an injection angle of 15 degrees or less. In this way, high pressure spraying of the grinding fluid is possible. Moreover, while the pressure becomes higher when the injection angle is 0 degree, the spray area to the abrasive surface becomes larger by adding the injection angle.

Further, in the polishing apparatus, preferably, the pressure sprayed by the grinding fluid spraying means is a high pressure of 10 MPa or more and 15 MPa or less. This is desirable not only in terms of the workability of the polishing operation but also in terms of cost.

Preferably, the polishing apparatus further comprises means for supplying a coolant to the polishing surface separately from the high-pressure grinding fluid sprayed onto the polishing surface of the diamond grindstone.

Further, the polishing apparatus may use purified water as the high-pressure grinding fluid and use purified water after being used as the grinding fluid in the coolant.

In addition, this polishing apparatus is carbonized by combining a CBN whetstone, an aluminous-based whetstone formed by bonding aluminous-based abrasive grains with a binder instead of the diamond whetstone, or a silicon carbide-based abrading grains with a binder. The present invention is also applicable to the case of using a silicon-based grindstone.

In the present invention, when a workpiece made of super alloy is polished while rotating a diamond grindstone, a high pressure grinding fluid is sprayed to the polishing surface (abrasive grain surface) while changing a portion to be sprayed, so clogging occurs. It is possible to wash away the abrasive powder causing the cause and continue the polishing operation for a long time without dressing. Therefore, it is possible to reduce the number of operations for removing one layer of the polishing surface (abrasive particle surface) clogged by the diamond dresser. In particular, not only spraying with high pressure, but also spraying while changing the site to be sprayed, it is possible to wash out clogging evenly.

It is a figure showing a schematic structure of a polish device concerning one embodiment of the present invention. It is a front view of the whetstone used for the above-mentioned polish device. It is a figure which shows schematic structure of the grinding | polishing apparatus which changed the rotating shaft of the grindstone of FIG. It is a comparison photograph with the grindstone surface which clogged, and the grindstone surface after using grinding fluid spraying means. It is a figure which shows schematic structure of the modification of the grinding device of FIG. It is a figure which shows the modification of the grindstone used for the grinding device of FIG. It is a figure which shows schematic structure of the grinding | polishing apparatus which concerns on another embodiment of this invention.

(Polishing apparatus of the present embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a schematic configuration of a polishing apparatus according to an embodiment of the present invention. FIG. 2 is a front view of a rotary grindstone used in a polishing apparatus.

As shown in FIGS. 1 and 2, the polishing apparatus 1 has a disc-shaped rotary grindstone 2 rotatably supported, and the rotary grindstone 2 has a binder of diamond abrasive grains around a core metal 2a. A diamond grindstone 2b to be bonded is provided. Then, at the time of polishing work, the rotary grindstone 2 is rotated at a constant speed around the horizontal rotation axis, and the polishing surface 2ba which is the side surface of the rotary grindstone 2 is made of superalloy such as Inconel (registered trademark). The workpiece W (for example, a cylindrical member or a cylindrical member) is polished.

The polishing apparatus 1 is provided with a grinding fluid spraying means 3 for spraying a high-pressure grinding fluid from the direction perpendicular to the polishing surface 2ba to the polishing surface 2ba in parallel with the grindstone 2 during polishing. In the present embodiment, for example, purified water containing a rust inhibitor, surfactant and the like and subjected to concentration control is used as the grinding fluid. And the pressure sprayed on grinding | polishing surface 2ba of the grindstone 2 is a high pressure of 8 Mpa or more and 50 Mpa or less (preferably 10 Mpa or more and 15 Mpa or less). Although the spraying direction by the nozzle 3 is orthogonal to the polishing surface 2ba, it may be inclined.

The grinding fluid spraying means 3 has a thin nozzle 3a connected to a pump (not shown), thereby enabling high pressure grinding fluid to be jetted. Further, the nozzle 3 a of the grinding fluid spraying means 3 is configured to be swingable with respect to the polishing surface 2 ba of the grindstone 2. By swinging the nozzle 3a of the grinding fluid spraying means 3, it becomes possible to spray the grinding fluid on a predetermined range of the polishing surface 2ba.

Further, the grinding liquid spraying position P1 by the grinding liquid spraying means 3 is set to a position different from the w-work grinding position P2 for grinding the work W. In the example shown in FIG. 1, the grinding fluid spray position P1 is at the lower position, and the workpiece polishing position P2 is at the upper position. As a result, in the rotating grindstone 2, the abrasive powder generated by spraying the grinding fluid on the grinding surface 2 ba flows downward, and the workpiece W is polished on the abrasive surface 2 ba from which the abrasive powder has been removed.

According to the apparatus 1, when the work W is polished by the polishing surface 2ba while rotating the disc-shaped rotary grindstone 2, the abrasive powder attached to the polishing surface 2ba of the rotary grindstone 2 is washed away by the high pressure grinding fluid While, the work W can be polished. This makes it possible to polish the work efficiently while suppressing clogging by the abrasive powder.

The spraying of the grinding fluid is performed at the grinding fluid spraying position P1 different from the workpiece polishing position P2 for polishing the workpiece W, and the polishing powder adhering to the polishing surface 2ba is washed away, and the workpiece W is polished. There is no risk of interfering with work.

In addition, since the grinding fluid is sprayed while moving at a high pressure of 8 Mpa or more from a position about 5 mm away from the direction orthogonal to the polishing surface 2ba, the high pressure grinding fluid acts to dig out the polishing powder and the polishing powder acts to polish The abrasive powder is washed away by overcoming the force to adhere to the surface 2ba. Therefore, for a long period of time, it is not necessary to cut the abrasive grain surface clogged with the diamond dresser by one layer.

In addition, since the grinding fluid spraying means 3 is configured to be able to swing between the inner diameter side portion and the outer diameter side portion in the radial direction with respect to the polishing surface 2 ba of the rotary grindstone 2, polishing for polishing the workpiece W The grinding fluid can be sprayed uniformly at a high pressure of 8 MPa or more over the predetermined range of the surface 2ba. As a result, since the work W can be polished while washing away the polishing powder attached to the polishing surface 2 ba for polishing the work W, efficient polishing is possible.

In the above embodiment, the rotary grindstone 2 is arranged to rotate around the horizontal rotation axis, but as shown in FIG. 3, it is arranged to rotate around the vertical rotation axis You may

(Effect of this embodiment)
According to the above-described polishing apparatus of the present embodiment, it is possible to suppress the removal of the layer in which a large number of expensive diamond abrasive grains exist by dressing the diamond grindstone, and to suppress the cost. In addition, since the diamond abrasive grains have extremely high hardness, it is difficult to grind with a maintenance grindstone or the like like a normal grindstone. However, by using the polishing apparatus of the present embodiment, the polished surface of the diamond grindstone The polishing performance can be recovered without clogging by grinding the diamond abrasive grains, which is a very revolutionary thing. The photograph which compared the surface of the clogged diamond whetstone with the surface of the diamond whetstone after using grinding fluid spraying means in FIG. 4 is shown.

(Modification 1)
Next, modifications of the above embodiment will be described. FIG. 5 is a view showing a schematic configuration of a polishing apparatus according to a modified embodiment. The same reference numerals are used for configurations common to the above embodiment.

The main difference between the polishing apparatus 10 of this modification and the polishing apparatus 1 of the above embodiment is that the polishing apparatus 1 of the above embodiment has a configuration in which the grinding liquid spraying means 3 swings, whereas The polishing apparatus 10 is a nozzle moving means (not shown) in which the grinding fluid spraying means 30 linearly reciprocates the nozzle 30a from the inner diameter side portion to the outer diameter side portion in the radial direction with respect to the grinding surface 2ba of the grinding wheel 2 ) Is a point.

According to this configuration, the nozzle 30a of the grinding fluid spraying means 30 reciprocates from the inner diameter side portion to the outer diameter side portion of the grinding surface 2ba of the grinding wheel 2 and sprays a high-pressure grinding fluid to the entire grinding surface 2ba. The grinding wheel can be ground uniformly throughout. As a result, when the workpiece is polished, the workpiece can be polished while washing away the polishing powder adhering to the entire polishing surface 2 ba, and efficient polishing can be performed. It is particularly suitable when the size of the work is large.

(Modification 2)
Moreover, FIG. 6 is a figure which shows schematic structure of the grinding device of embodiment of another modification. As shown in FIG. 6, the disk-like work support board 40 is provided with its rotation axis eccentrically in the radial direction with respect to the rotation axis of the rotary grindstone 2, and the side surface of the work support board 40 on the rotary grindstone 2 side A plurality of works W are supported in the circumferential direction at regular intervals, and each work W is polished by the rotating whetstone 2 while rotating the work supporting disc 40 in a direction opposite to the rotating direction of the rotating whetstone 2, for example The polishing workability can also be enhanced by polishing the plurality of workpieces W together.

(Other embodiments)
As described above, although the preferred embodiments of the present invention have been described with reference to the drawings, various additions, modifications, or deletions can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the diamond grindstone is used as the grindstone, but the present invention can also be applied to a CBN (Borazon) grindstone, an alumina-based grindstone, a silicon carbide-based grindstone, and the like. Further, the shape of the grindstone is not limited to the shape of the present embodiment, and a grindstone of another shape may be used (see, for example, FIG. 7).

Moreover, although the side surface (plane) of a grindstone is used as a grinding | polishing surface in this embodiment, you may use the grindstone which makes the surrounding surface (curved surface) of a grindstone a grinding | polishing surface. In addition, it is also possible to collect the sprayed liquid, filter it once and then to flow separately to the polishing surface 2 ba separately from the sprayed liquid to be used as a coolant for cooling the polishing site. Therefore, such is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Polishing device 2 Rotating grindstone 2a Core metal 2b Diamond grindstone 2ba Polishing surface 3 Grinding fluid spraying means 3a Nozzle 10 Polishing device 30 Grinding fluid spraying means 30a Nozzle 40 Work support board P1 Grinding fluid spraying position P2 Work polishing position W Work

Claims

A polishing method for polishing a workpiece made of superalloy while rotating a diamond grinding wheel formed by bonding diamond abrasive grains with a binder,
The workpiece is polished while spraying a high-pressure grinding fluid while changing a portion to be sprayed on the polishing surface of the diamond grindstone for polishing the workpiece.
Polishing method.
The grinding fluid is sprayed on the grinding surface of the diamond grinding wheel at a high pressure of 8 MPa to 50 MPa and separated from the direction orthogonal to the polishing surface at a position different from the position where the workpiece is polished, at a high pressure of 8 MPa to 50 MPa.
The polishing method according to claim 1.
Spraying of the grinding fluid is linear injection at an injection angle of 0 degrees or injection within an injection angle of 15 degrees.
The polishing method according to claim 2.
The pressure applied to the polishing surface of the diamond grindstone is a high pressure of 10 MPa or more and 15 MPa or less.
The polishing method according to claim 3.
The diamond grinding wheel has an annular grinding surface having a fixed length in the radial direction,
Swinging a portion to which the grinding fluid is sprayed to the polishing surface between the inner diameter side portion and the outer diameter side portion in the radial direction;
The polishing method according to claim 1.
Apart from the high pressure grinding fluid sprayed on the grinding surface of the diamond wheel,
Polishing the workpiece while supplying a coolant to the polishing surface;
The polishing method according to claim 2.
Using purified water as the high pressure grinding fluid,
Using purified water after being used as the grinding fluid as the cooling fluid,
A polishing method according to claim 6.
Instead of the diamond grindstone, a CBN grindstone, an alumina-based grindstone formed by bonding alumina-based abrasives with a binder, or a silicon carbide-based grindstone formed by bonding silicon carbide-based abrasives with a binder is used.
The polishing method according to any one of claims 1 to 7.
A polishing apparatus for polishing a workpiece made of super alloy while rotating a diamond grinding wheel formed by bonding diamond abrasive grains with a binder,
The apparatus further comprises a grinding fluid spraying means for spraying a grinding fluid at a high pressure through a nozzle from a direction perpendicular to the polishing surface on the polishing surface of the diamond grindstone during polishing.
The grinding fluid spraying means is characterized by having a nozzle moving means for changing the spraying site of the grinding fluid by moving the nozzle.
Polishing device.
The diamond grinding wheel has an annular grinding surface having a fixed length in the radial direction,
The nozzle moving means swings the nozzle between an inner diameter side portion and an outer diameter side portion in a radial direction with respect to the polishing surface at a position different from a polishing position for polishing the workpiece.
A polishing apparatus according to claim 9.
The grinding fluid spraying means can spray the grinding fluid at a high pressure of 8 MPa or more and 50 MPa or less.
A polishing apparatus according to claim 9.
The nozzle is a nozzle in which the spray of the grinding fluid is a linear injection at an injection angle of 0 degrees or an injection within an injection angle of 15 degrees.
A polishing apparatus according to claim 11.
The pressure sprayed by the grinding fluid spraying means is a high pressure of 10 MPa or more and 15 MPa or less.
A polishing apparatus according to claim 12.
A means for supplying a cooling fluid to the polishing surface is further provided separately from the high-pressure grinding fluid sprayed onto the polishing surface of the diamond grindstone.
The polishing apparatus according to claim 10.
Using purified water as the high pressure grinding fluid and using purified water after being used as the grinding fluid as the cooling fluid,
The polishing apparatus according to claim 14.
Instead of the diamond grindstone, a CBN grindstone, an alumina-based grindstone formed by bonding alumina-based abrasives with a binder, or a silicon carbide-based grindstone formed by bonding silicon carbide-based abrasives with a binder is used.
A polishing apparatus according to any one of claims 9 to 15.