WO2016166852A1

WO2016166852A1 - Abrasive material and rotary polishing tool

Info

Publication number: WO2016166852A1
Application number: PCT/JP2015/061616
Authority: WO
Inventors: 松下　俊; 誠一藤沢; 慶彦住吉
Original assignee: 大明化学工業株式会社; 株式会社ジーベックテクノロジー
Priority date: 2015-04-15
Filing date: 2015-04-15
Publication date: 2016-10-20

Abstract

A rotary polishing tool (1) comprises: an abrasive material (2); an abrasive material holder (3); a shank (4); and a universal joint (5) that connects the abrasive material holder (3) and the shank (4) to each other. The abrasive material (2) includes a cylindrical trunk (13) in which first aggregate yarn (11) and second aggregate yarn of inorganic long fibers are fixed to each other with a resin. Each aggregate yarn (11, 12) extends in a direction that is inclined at an angle smaller than 45° with respect to an axial line L from a front annular end surface (13a) side toward a rear annular end surface (13b) side. The front annular end surface (13a) is a polishing surface and front end surfaces of the aggregate yarns (11, 12) are exposed thereat.

Description

Abrasive materials and rotary polishing tools

The present invention relates to an abrasive material in which an aggregate yarn of inorganic long fibers is hardened with a resin, and a rotary polishing tool having such an abrasive material.

A metal bond grindstone is used to remove EDM traces on the mold. In a metal bond grindstone, diamond particles as abrasive grains are dispersed and held in a metal base material such as brass.

JP 2013-166204 A

Since the metal bond grindstone has a large grinding force, the EDM trace can be removed in a relatively short time. However, when a metal bond grindstone is used, there is a problem that the surface accuracy of the mold after the electric discharge machining trace is removed is low. Therefore, it takes time for finish polishing performed in the subsequent steps.

In view of such a point, an object of the present invention is to provide an abrasive and a rotary polishing tool having high surface accuracy after processing while having a large grinding force.

In order to solve the above-mentioned problems, the abrasive of the present invention has a cylindrical body portion in which a collection yarn of a plurality of inorganic long fibers is hardened with a resin, and the body portions are positioned at both ends in the axial direction. A first annular end face and a second annular end face, each aggregate yarn extending in a direction parallel to the axis or inclined at an angle smaller than 45 ° with respect to the axis, wherein the first annular end face It is a polished surface where the end face of the aggregate yarn is exposed.

In the present invention, the aggregate yarn of the inorganic long fibers is parallel to the axis of the trunk or inclined at an angle smaller than 45 °, and its end face is exposed on the polishing surface of the abrasive. Thereby, the end surface of the collective yarn that becomes the cutting edge comes into contact with the surface to be polished of a workpiece such as a mold at an angle of 45 ° or more. Therefore, the grinding force by the abrasive is large, and even the work of difficult-to-work material such as a mold can be polished and ground. Moreover, since the trunk | drum which hardened the aggregate thread | yarn of the inorganic long fiber with resin is soft compared with a metal bond grindstone provided with a metal base material, it bends following the surface shape of the workpiece. Furthermore, since the abrasive is cylindrical and its annular end surface is a polished surface, the workpiece is not only a flat surface, but also the surface of the workpiece as compared with the case where the entire end surface of the columnar abrasive is a polished surface. Even when a convex curved surface is provided, polishing / grinding along the surface can be performed. Also, since the abrasive is cylindrical and its annular end surface is a polishing surface, the abrasive that contacts the workpiece during rotation compared to the case where the end surface of the columnar abrasive is an abrasive surface. The peripheral speed of the portion is constant, the behavior is stable, and the abrasive wear is uniform. As a result, since the shape of the polished surface does not change and the processing conditions are stabilized, polishing and grinding can be performed without breaking the shape of the workpiece surface. Therefore, the surface accuracy of the workpiece by polishing and grinding is improved.

In the present invention, it is preferable that the body portion includes a slit formed from the first annular end face toward the second annular end face. If such a slit is provided, cutting waste is removed from the slit to the outer peripheral side of the abrasive during polishing and grinding operations. Therefore, the clogging due to the cutting waste can be prevented, and the reduction of the grinding force of the abrasive and the heat generation of the workpiece can be suppressed. In addition, the formation of the slit makes it possible to appropriately adjust the pressure of the abrasive during polishing / grinding, and the self-generating action of bringing out a new cutting edge becomes active.

In the present invention, in order to provide a cylindrical body portion, the body portion is cut out from a columnar abrasive base material formed by consolidating an aggregate yarn of a plurality of inorganic long fibers with a resin. be able to.

In the present invention, the collective yarn is inclined at an angle smaller than 45 ° with respect to the axis, and as the collective yarn, a plurality of first collective yarns oriented in a first direction, the first direction, It is desirable to provide a plurality of second aggregate yarns arranged in the intersecting second direction. By doing so, the aggregate yarn that becomes the cutting edge includes the first aggregate yarn and the second aggregate yarn that are inclined in different directions, so that the grinding force of the abrasive is increased. Further, since the strength of the cylindrical portion is increased by the gathered yarns oriented in two directions, even when the slit 15 is formed in the barrel portion, the barrel portion 13 is not damaged, and the durability of the abrasive material is improved.

Next, the rotary polishing tool of the present invention connects the abrasive, the abrasive holder that holds the abrasive from the second annular end surface side, the shank, and the shank and the abrasive holder. And a universal joint.

According to the present invention, since the shank and the abrasive holder are connected by the universal joint, the polishing surface of the abrasive can be displaced along the surface of the workpiece while the shank is held by a power tool or the like. . Therefore, the surface accuracy of the workpiece by polishing and grinding is improved.

It is the perspective view and front view of a rotary polishing tool to which the present invention is applied. It is a disassembled perspective view of the rotary polishing tool of FIG. It is explanatory drawing of the manufacturing method of an abrasive. It is explanatory drawing of the edge part of the abrasive material base material which grinds an abrasive material. It is a graph which shows the relationship between the grinding | polishing time by a rotary grinding | polishing tool, and surface roughness. It is a graph which shows the relationship between polishing time and surface roughness until completion | finish of metal mold | die final polishing is completed.

Hereinafter, a rotary polishing tool to which the present invention is applied will be described with reference to the drawings.

(Rotary polishing tool)
Fig.1 (a) is a perspective view at the time of seeing the rotary polishing tool which concerns on this invention from diagonally upward ahead, FIG.1 (b) is a front view of a rotary polishing tool. FIG. 2 is an exploded perspective view of the rotary polishing tool. The rotary polishing tool 1 is used by being connected to a hand-held power machine or machine tool, and is used for polishing and grinding such as removal of electric discharge machining marks and deburring of a mold.

As shown in FIG. 1A, a rotary polishing tool 1 includes a cylindrical abrasive material 2, an abrasive material holder 3 that holds the abrasive material 2, a shank 4 that is connected to the head of a power machine, and an abrasive material. A universal joint 5 for connecting the holder 3 and the shank 4 is provided. The universal joint 5 is a joint that can freely change the angle between the abrasive material holder 3 and the shank 4, and has a general configuration. In the following description, the direction along the axis L of the abrasive 2 is the front-rear direction X, the side where the abrasive 2 is located is the front X1, and the side where the shank 4 is located is the rear X2, and the abrasive 2 and rotational polishing. The tool 1 will be described. Further, when polishing or deburring a workpiece with the rotary polishing tool 1, the abrasive exhibits an effect close to that of grinding. Therefore, in the following description, polishing and grinding are used without distinction.

As shown in FIGS. 1 and 2, the abrasive 2 has a cylindrical body portion 13 in which an aggregate yarn 10 of a plurality of inorganic long fibers is hardened with a resin. The body portion 13 includes a front annular end face (first annular end face) 13a located at the front end and a rear annular end face (second annular end face) 13b located at the rear end. Each aggregate yarn 10 extends from the front annular end surface 13a side toward the rear annular end surface 13b side. The front annular end surface 13a is a polished surface from which the front end surface 10a of the collective yarn 10 is exposed. The body portion 13 includes, as the aggregate yarn 10, a plurality of first aggregate yarns 11 that are oriented in the first direction and a second aggregate yarn 12 that is oriented in the second direction intersecting the first direction. FIG. 1A schematically shows a single first aggregate yarn 11 oriented in the first direction and a second aggregate yarn 12 oriented in the second direction.

Moreover, the trunk | drum 13 is provided with the several slit 15 formed toward the back side annular end surface 13b side from the front side annular end surface 13a. In this example, eight slits 15 are provided at equal angular intervals around the axis L.

The abrasive holder 3 is made of metal. As shown in FIG. 2, the abrasive material holder 3 includes a cylindrical portion 16 and a flange portion 17 that spreads from an intermediate position of the cylindrical portion 16 in the front-rear direction X to the outer peripheral side. A front X1 of the flange portion 17 in the cylindrical portion 16 is an insertion portion 18 that is inserted into the body portion 13 of the abrasive 2 from the rear X2 (the rear annular end surface 13b side). The insertion part 18 is inserted into the body part 13 and fits into the center hole 13 c of the body part 13.

The insertion portion 18 is inserted into the body portion 13 until the front end surface of the flange portion 17 comes into contact with the rear annular end surface 13b of the abrasive 2. In a state where the insertion portion 18 is inserted into the body portion 13, the insertion portion 18 holds the rear end portion (portion where the slit 15 is not formed) of the body portion 13 from the inside. The abrasive material 2 is fixed to the abrasive material holder 3 by an adhesive interposed between the outer peripheral surface of the insertion portion 18 and the front end surface of the flange portion 17 and the body portion 13. A portion of the cylindrical portion 16 that is behind the flange portion 17 from the flange portion 17 is a holder side connection portion 19 that connects the shank 4 via the universal joint 5.

Shank 4 is made of metal. The shank 4 includes a shaft portion 21 having a constant outer diameter and a shank side connection portion 22 provided in front X1 of the shaft portion 21. The shank side connection portion 22 includes a pair of

support arms

23 and 24 that face each other in a direction orthogonal to the axis L. A connecting rod 25 is inserted between the pair of

support arms

23 and 24 so as to extend in a direction orthogonal to the opposing direction of the

support arms

23 and 24.

The connecting rod 25 is supported by the pair of

support arms

23 and 24 so as to be rotatable around a rotation axis extending orthogonally to the axis L and extending in a direction opposite to the

support arms

23 and 24. Both ends 25a and 25b of the connecting rod 25 are held by holding

portions

19a and 19b provided on the holder-side connecting portion 19 in a state where both ends 25a and 25b can rotate in the front-rear direction X, respectively. The shank side connection part 22, the connecting rod 25 and the holder side connection part 19 constitute a universal joint 5.

Here, as shown in FIG. 1, since the abrasive material holder 3 is cylindrical, the center of the abrasive material 2 (body portion 13) from the side of the shank 4 with the shank 4 connected via the universal joint 5. A through-hole 30 communicating with the hole 13c is provided.

(Abrasive material)
Abrasive material 2 (body portion 13) is a thermoset of silicon resin, phenol resin, epoxy resin, polyimide resin, polymaleimide resin, unsaturated polyester resin, urethane resin or the like on aggregate yarn 10 of alumina long fibers as inorganic long fibers. It is impregnated and cured with a functional binder resin or a thermoplastic resin such as nylon. The aggregate yarn 10 is an aggregate of 250 to 3000 alumina long fibers having a fiber diameter of 8 to 50 μm. The diameter of the aggregate yarn 10 is 0.1 mm to 2 mm. The aggregate yarn 10 may be twisted. As the inorganic long fiber, alumina carbide, silicon carbide fiber, boron fiber, or the like can be used.

In this example, as the aggregate yarn 10, a plurality of first aggregate yarns 11 oriented in the first direction with a predetermined interval and a predetermined interval in the second direction intersecting the first aggregate yarn 11. A plurality of second aggregate yarns 12 are provided. Each of the first collective yarn 11 and the second collective yarn 12 extends from the front annular end surface 13a side to the rear annular end surface 13b side in a direction inclined at an angle smaller than 45 ° with respect to the axis L. . As schematically shown in FIG. 1A, in this example, the angle at which each of the first aggregate yarn 11 and the second aggregate yarn 12 is inclined with respect to the axis L is 10 ° or more and 20 ° or less. . The end surface of the first aggregate yarn 11 and the end surface of the second aggregate yarn 12 are exposed at the front annular end surface 13a.

FIG. 3 is an explanatory diagram of a method for manufacturing the abrasive 2. FIG. 4 is an explanatory view of an end portion of the abrasive base material for scraping the abrasive 2 (body portion 13). When manufacturing the abrasive 2, first, as shown in FIG. 3 (a), the first aggregate yarn 11 of inorganic long fibers impregnated with resin by submerging the resin tank is made to have a cylindrical rotating body 41. A first winding process is performed. In the first winding step, the first collective yarn 11 is tilted in the first direction in the circumferential direction with respect to the outer circumferential surface 41a along the rotation direction of the rotating body 41 (while tilting from 10 ° to 20 °). Take up at intervals. Next, as shown in FIG. 3B, a second winding process is performed in which the second aggregate yarn 12 of inorganic long fibers impregnated with the resin is wound around the rotating body 41 by immersing the resin tank. In the second winding step, the second aggregate yarn 12 is tilted in a second direction inclined with respect to the first direction (inclined by 10 ° to 20 ° on the side opposite to the first collective yarn 11), at a predetermined interval. Open and wind up. Then, the first winding process and the second winding process are repeated a plurality of times in this order. Thereby, as shown in FIG. 3C, the first aggregate yarn 11 and the second aggregate yarn 12 impregnated with the resin are laminated on the outer peripheral surface of the rotating body 41.

Here, the first winding process and the second winding process are an operation of moving one aggregate yarn 10 in the direction of the axis L of the rotating body 41 in a state where the rotating body 41 is rotated around the axis L1. The assembly yarn 10 can be continuously performed by repeating the operation of turning in the reverse direction when it reaches the end portion of the rotating body 41. In addition, by making the angle of inclination symmetrical between the first aggregate yarn 11 and the second aggregate yarn 12, the abrasive 2 exhibits a stable grinding force.

Next, as shown by a two-dot chain line C <b> 1 in FIG. 3C, the molding material 42 wound on the rotating body 41 is cut and opened along the axis L direction of the rotating body 41. Thereby, as shown in FIG.3 (d), the molding material 42 is made into a sheet form. Then, as shown in FIG. 3 (e), the sheet-shaped molding material 42 is cured by heating and pressing in a single body or in a state where a plurality of the molding materials 42 are stacked. Thereby, the inorganic long fiber reinforced resin body 43 in which the

aggregate yarns

11 and 12 of the inorganic long fibers are hardened with the resin is formed.

Thereafter, as shown by a two-dot chain line C2 in FIG. 3 (e), the inorganic long fiber reinforced resin body 43 is cut. Thereby, as shown in FIG. 3F, a columnar abrasive base material 44 is formed. As shown in FIG. 4, in the abrasive base material 44, the extending direction of the first aggregate yarn 11 and the second aggregate yarn 12 is 20 ° with respect to the axis L of the abrasive base material 44 (axis of the body portion 13). It is inclined at the following angle.

Thereafter, the body portion 13 is cut out from the abrasive base material 44. That is, as shown by a two-dot chain line C3 in FIG. 3 (f), the abrasive base material 44 is divided into long dimensions corresponding to the body portion 13, and the through hole penetrates the abrasive base material 44 in the axis L direction. 30 is provided, and the outer peripheral surface of the abrasive base material 44 is cut into a circular shape. Thereby, the trunk | drum 13 shown in FIG.3 (g) is scraped off from the abrasive material base material 44. FIG.

Thereafter, the body portion 13 is cut to provide the slit 15. Thereby, as shown in FIG.3 (h), the trunk | drum 13 (abrasive material 2) is completed. In addition, since the trunk | drum 13 is formed from the inorganic long fiber reinforced resin body 43, even when the trunk | drum 13 is formed thinly, it is not cracked or chipped. Further, since the

aggregate yarns

11 and 12 are oriented in two directions intersecting each other in the inorganic long fiber reinforced resin body 43, the strength of the body portion 13 formed from the inorganic long fiber reinforced resin body 43 is high, and the slit 15 The body portion 13 is not damaged by the formation. Furthermore, since the collecting

yarns

11 and 12 are oriented in two directions intersecting each other, the durability of the abrasive 2 is high.

(Machining operation)
The shank 4 is connected to the head of the power machine when performing polishing for removing the electric discharge machining trace of the mold (work) for resin molding using the rotary polishing tool 1 of this example. Then, the rotary polishing tool 1 is rotated about the axis L, and the polishing surface (front-side annular end surface 13a) of the abrasive 2 is brought into contact with the portion to be polished of the mold.

In this example, the first aggregate yarn 11 and the second aggregate yarn 12 of the inorganic long fibers are inclined at an angle of 20 ° or less with respect to the axis L of the trunk portion 13, and the front surface is the polishing surface of the abrasive 2 It is exposed on the annular end surface 13a. Thereby, the end surface of the 1st collective yarn 11 used as a cutting edge and the end surface of the 2nd collective yarn 12 contact at an angle of 70 degrees or more with respect to the to-be-polished surface of a metallic mold. Therefore, the grinding force by the abrasive 2 is high, and the surface of even a difficult-to-work workpiece such as a mold can be polished.

Here, the body portion 13 in which the

aggregate yarns

11 and 12 of the inorganic long fibers are hardened with a resin is softer than a metal bond grindstone or the like provided with a metal base material, and therefore follows the surface shape of the surface to be polished. Bend. Further, since the front annular end surface 13a of the cylindrical body portion 13 is a polishing surface, the mold is not only a flat surface but also a mold as compared with the case where the entire end surface of the columnar abrasive is a polishing surface. Even when the surface has a convex curved surface, polishing and grinding along the surface can be performed. Moreover, since the abrasive 2 is cylindrical and the front-side annular end surface 13a is a polishing surface, compared to the case where the end surface of a columnar abrasive is an abrasive surface, the mold is rotated during the rotation. The peripheral speed of the portion of the abrasive material that comes into contact is constant, the behavior is stable, and the wear of the abrasive 2 is uniform. As a result, the shape of the polishing surface of the abrasive material 2 does not change and the processing conditions are stabilized, so that polishing and grinding can be performed without breaking the shape of the mold surface.

Further, since the shank 4 and the abrasive holder 3 are connected by the universal joint 5, the polishing surface of the abrasive 2 is displaced along the surface of the mold while the shank 4 is held by a power tool or the like. Can do. Therefore, according to the rotary polishing tool 1 of this example, the surface accuracy of the mold by polishing is improved.

Moreover, in this example, since the trunk | drum 13 is provided with the slit 15, the cutting waste which generate | occur | produces during processing operation is removed to the outer peripheral side of the abrasive material 2. FIG. Therefore, clogging due to cutting waste can be prevented, and the reduction of the grinding force of the abrasive 2 and the heat generation of the workpiece can be suppressed. Moreover, the pressure of the abrasive material 2 at the time of grinding | polishing and grinding can be adjusted appropriately by formation of a slit, and the self-generated action which brings out a new cutting edge becomes active. Furthermore, in this example, since the abrasive material holder 3 is provided with the through-hole 30 connected to the center hole 13c of the abrasive material 2 from the shank 4 side, heat dissipation is good, and the inside of the abrasive material 2 through the through-hole 30 is carried out. Air can be supplied.

FIG. 5 is a graph showing the relationship between the polishing time and the surface roughness when polishing is performed to remove the EDM traces of the mold using the rotary polishing tool 1 of this example and the rotary polishing tool of the comparative example. is there. FIG. 5A shows the relationship between polishing time and surface roughness (arithmetic average roughness Ra), and FIG. 5B shows the relationship between polishing time and surface roughness (maximum height Rz). The rotary polishing tool of the comparative example is manufactured by NOVAPAX, and includes a metal bond grindstone (grain size # 150) in which diamond abrasive grains are dispersed and held in a cylindrical grindstone made of brass. Moreover, the grindstone of the rotary polishing tool of the comparative example has substantially the same shape as the abrasive 2 (body 13) of the rotary polishing tool 1 of this example. The mold material is plastic mold steel (NAK80: manufactured by Daido Steel Co., Ltd.). In the polishing process, the rotational speed of each rotary polishing tool was 3000 min−1, the pressing force was 2 N, and the grinding area was 3 cm × 3 cm.

FIG. 6 shows the polishing time and surface roughness in the case of performing polishing until the final polishing after performing polishing that removes the electric discharge machining trace of the mold using the rotary polishing tool 1 of this example and the rotary polishing tool of the comparative example. It is a graph which shows the relationship of a degree. FIG. 6A shows the relationship between polishing time and surface accuracy (arithmetic mean roughness Ra), and FIG. 6B shows the relationship between polishing time and surface accuracy (maximum height Rz). The final polishing was performed wet using a brass cylindrical grindstone and diamond paste (grain size # 800).

As shown in FIGS. 5 (a) and 5 (b), the time to complete the electric discharge machining trace removal is 2 minutes when the rotary polishing tool 1 of this example is used to remove the electric discharge machining trace of the mold. 30 seconds, which is 15% or more shorter than 3 minutes when the rotary polishing tool of the comparative example is used.

Further, when the rotary polishing tool 1 of this example is used as shown in FIG. 5A, the arithmetic average roughness Ra of the mold at the time when the removal of the electric discharge machining trace is completed is 0.29 μm. Compared to 0.70 μm in the case of using the rotary polishing tool of the comparative example, it was reduced by 58% or more. Further, when the rotary polishing tool 1 of this example is used, as shown in FIG. 5B, the maximum height Rz at the time when the removal of the electric discharge machining trace is completed is 2.9 μm, Compared to 4.7 μm when a rotary polishing tool was used, it was reduced by 38% or more.

Further, as shown in FIGS. 6 (a) and 6 (b), when the rotary polishing tool 1 of this example is used, the time until the finish polishing is completed is 12 minutes 30 seconds. Compared to 23 minutes when using a polishing tool, the time to finish polishing was reduced by 45% or more.

In the above example, the collective yarn 10 constituting the body portion 13 is inclined with respect to the axis L of the body portion 13, but may extend in parallel to the axis L. Further, the slit 15 can be omitted.

Claims

It has a cylindrical body part in which an aggregate yarn of a plurality of inorganic long fibers is hardened with a resin,
The trunk includes a first annular end surface and a second annular end surface located at both ends in the axial direction,
Each aggregate yarn extends in a direction parallel to the axis or inclined at an angle smaller than 45 ° with respect to the axis,
The abrasive material, wherein the first annular end surface is a polished surface from which an end surface of each aggregate yarn is exposed.
In claim 1,
The said trunk | drum is equipped with the slit formed toward the said 2nd annular end surface side from the said 1st annular end surface, The abrasive | polishing material characterized by the above-mentioned.
In claim 1,
The said trunk | drum is shaved from the column-shaped abrasive | polishing material base material formed by solidifying the aggregate yarn of a plurality of inorganic long fibers with resin, The abrasive | polishing material characterized by the above-mentioned.
In claim 1,
The assembly yarn is inclined at an angle smaller than 45 ° with respect to the axis;
The aggregate yarn includes a plurality of first aggregate yarns oriented in a first direction and a plurality of second aggregate yarns arranged in a second direction intersecting the first direction, Abrasive material.
The abrasive according to claim 1;
An abrasive holder for holding the abrasive from the second annular end face;
Shank,
A universal joint connecting the shank and the abrasive holder;
A rotary polishing tool comprising: