JP5115004B2 - Chamfering device, chamfering method and sintered magnet - Google Patents

Description

  The present invention relates to a chamfering device, a chamfering method, and a sintered magnet, and more particularly to a chamfering device and a chamfering method for chamfering a circular outer peripheral edge of a sintered magnet, and a sintered magnet having a chamfered outer peripheral edge.

  Generally, a chamfered surface is provided on the outer peripheral edge of a cylindrical permanent magnet used in a motor or the like in order to easily form a surface treatment film during surface treatment or to prevent chipping during motor assembly. It is formed. As a device for chamfering the outer peripheral edge of a permanent magnet, a chamfering device is known in which the outer peripheral edge of a permanent magnet is pressed against the tapered inner peripheral surface of a cup-type grindstone. However, in such a chamfering device, since the permanent magnet is in contact with a specific portion of the inner peripheral surface of the grindstone, there is a problem that the inner peripheral surface of the grindstone is unevenly worn linearly and the life of the grindstone is short.

In order to solve such a problem, for example, in Patent Document 1, while rotating a cylindrical workpiece and a columnar grindstone arranged so that one rotating shaft is inclined with respect to the other rotating shaft, A chamfering device for reciprocating a grindstone in the axial direction is disclosed. According to the technique of Patent Document 1, uneven wear of the grindstone can be suppressed, and the life of the grindstone can be extended. In the chamfering device of Patent Document 1, it is structurally difficult to move the grindstone in the axial direction at a speed larger than the peripheral speed of the outer peripheral edge of the work and the peripheral speed of the outer peripheral face of the grindstone. It is considered that polishing eyes extending in the circumferential direction are formed.
JP 2001-179580 A

  Normally, a chamfered workpiece is subjected to barrel processing for removing burrs and rounding corners. However, in a work in which long cuffs extending in the circumferential direction are formed on the chamfered surface, there is a problem that the chamfered surface and the vicinity thereof are easily chipped along the long crevice during barrel treatment. This problem is remarkable when a brittle sintered magnet such as a rare earth sintered magnet is used as the workpiece.

Therefore, a main object of the present invention is to provide a chamfering apparatus and a chamfering method which can extend the life of a grindstone and can form a short polishing mark on a chamfered surface.
Another object of the present invention is to provide a sintered magnet that is not easily chipped.

In order to achieve the above object, a chamfering device according to claim 1 is a chamfering device for a cylindrical or columnar sintered magnet having a circular outer peripheral edge, and includes a cylindrical grindstone and the sintered magnet. First rotating means for rotating in the circumferential direction; second rotating means for rotating the grindstone in the circumferential direction so that the peripheral speed of the outer peripheral surface of the grindstone is larger than the peripheral speed of the outer peripheral edge of the sintered magnet; Arrangement means for arranging the magnet and the grindstone so that one rotation axis is inclined by 90 ° with respect to the other rotation axis and one rotation axis does not cross the other rotation axis, and the outer peripheral edge of the sintered magnet is First moving means for moving at least one of the sintered magnet and the grindstone to the other side so as to be in contact with the outer circumferential surface of the grindstone, and the outer peripheral edge of the sintered magnet reciprocate on the outer circumferential surface of the grindstone A small amount of the sintered magnet and the grindstone move so as to move. Ku comprising a second moving means for moving either the axial direction of the grinding wheel even, said positioning means includes a rotatable pawl with the rotating portion and the rotating portion which is rotated by said first rotating means, said By sandwiching the outer peripheral surface of the sintered magnet with claws, the sintered magnet is held so as to be coaxial with the rotating portion and so that the end surface of the sintered magnet faces directly below .

The chamfering method according to claim 2 is a chamfering method for chamfering a circular outer peripheral edge of a cylindrical or columnar sintered magnet, wherein one of the rotating shafts of the sintered magnet and the cylindrical grindstone is the other. The step of disposing 90 ° with respect to the rotation axis and one rotation axis not intersecting the other rotation axis, the peripheral speed of the outer peripheral surface of the grindstone is larger than the peripheral speed of the outer peripheral edge of the sintered magnet Rotating the sintered magnet and the grindstone in the circumferential direction as described above, and at least one of the sintered magnet and the grindstone so that the outer peripheral edge of the sintered magnet is in contact with the outer peripheral surface of the grindstone Moving at least one of the sintered magnet and the grindstone in the axial direction of the grindstone so that the outer peripheral edge of the sintered magnet reciprocates on the outer peripheral surface of the grindstone while moving in equipped with, said arranging step By sandwiching the outer peripheral surface of the sintered magnet with a claw that can rotate together with the rotating part, the sintered magnet is held coaxially with the rotating part and so that the end face of the sintered magnet faces directly below, In the rotating step, the sintered magnet held by the claw is rotated in the circumferential direction by rotating the rotating portion in the circumferential direction .

  In the chamfering apparatus according to claim 1, the sintered magnet and the grindstone are arranged such that one rotation axis is inclined by 90 ° with respect to the other rotation axis and one rotation axis does not intersect the other rotation axis. The peripheral speed of the outer peripheral surface of the grindstone is rotated so as to be larger than the peripheral speed of the outer peripheral edge of the sintered magnet. Then, at least one of the sintered magnet and the grindstone so that the outer peripheral edge reciprocates on the outer peripheral surface while moving at least one of the sintered magnet and the grindstone to the other side so that the outer peripheral edge is in contact with the outer peripheral surface. One of them is moved in the axial direction of the grindstone. By disposing and relatively moving the sintered magnet and the grindstone in this way, the outer peripheral surface of the sintered magnet can be chamfered effectively using the outer peripheral surface of the grindstone, and the life of the grindstone can be extended. In addition, by arranging the sintered magnet and the grindstone in this way and rotating them so that the peripheral speed of the outer peripheral surface is larger than the peripheral speed of the outer peripheral edge, the outer peripheral edge is ground in the substantially radial direction of the sintered magnet. it can. As a result, it is possible to form a short polishing line extending in the circumferential direction on the chamfered surface of the sintered magnet. The same applies to the chamfering method according to claim 2.

According to the present invention, it is possible to extend the life of the grindstone and to form short polishing marks on the chamfered surface of the sintered magnet.
Moreover, a sintered magnet that is difficult to chip can be obtained.

Embodiments of the present invention will be described below with reference to the drawings.
Referring to FIG. 1, the chamfering device 10 chamfers the circular outer peripheral edge 102 of the sintered magnet 100 {see FIG. 2 (a)}, whereby the sintered magnet 100a having the chamfered surface 104 {FIG. 2 (b). ) Reference}. Cylindrical sintered magnet 100 is a rare earth sintered magnet such as an Nd-Fe-B magnet, and sintered magnet 100a obtained by chamfering sintered magnet 100 is used for a motor or the like, for example.

  As shown in FIG. 1, the chamfering device 10 includes a holding unit 12 and a grindstone unit 14. The holding unit 12 includes a base 16, a robot arm 18 provided on the base 16, and a robot hand 20 provided on the robot arm 18.

The robot arm 18 includes a support unit 21 provided on the base 16, a rotation unit 22 provided on the support unit 21, a first arm 24 coupled to the rotation unit 22, and a second arm coupled to the first arm 24. 26 and a third arm 28 coupled to the second arm 26.
The support unit 21 includes a motor 30 for rotating the rotating unit 22 around a rotation axis extending in the vertical direction (arrow A direction).

  The first arm 24 is connected to the rotating portion 22 via a connecting shaft 31a extending in a direction orthogonal to the paper surface of FIG. 1 (one direction in the horizontal direction), and the rotating portion 22 with the connecting shaft 31a as a fulcrum by a servo motor (not shown). Is swung with respect to. The second arm 26 is connected to the first arm 24 via a connecting shaft 31b parallel to the connecting shaft 31a, and is swung with respect to the first arm 24 about the connecting shaft 31b by a servo motor (not shown). The third arm 28 is connected to the second arm 26 via a connecting shaft 31c parallel to the connecting shafts 31a and 31b, and is swung relative to the second arm 26 by a servo motor (not shown) with the connecting shaft 31c as a fulcrum. . By such swinging of the first arm 24, the second arm 26, and the third arm 28, the robot hand 20 and consequently the sintered magnet 100 held by the robot hand 20 are moved in the directions indicated by arrows A and B (other than the horizontal direction). In at least one of the directions). That is, the robot arm 18 is configured to be able to perform linear interpolation operation of the three arms of the first arm 24, the second arm 26, and the third arm 28, and moves the robot hand 20 (sintered magnet 100) in the direction of arrow A and Move in at least one of the directions of arrow B.

  The third arm 28 includes a drive unit 32 coupled to the second arm 26 and a columnar rotation unit 34 that is rotatably provided to the drive unit 32. One end of the rotating unit 34 is connected to a motor 36 provided in the driving unit 32. A robot hand 20 that holds the workpiece 100 is provided at the other end of the rotating unit 34. The robot hand 20 is configured in a so-called three-claw shape having three claws 38. The robot hand 20 holds the sintered magnet 100 coaxially with the rotating portion 34 by sandwiching the outer peripheral surface 106 of the sintered magnet 100 with the three claws 38.

  In such a holding unit 12, the sintered magnet 100 is held so that the end face 108 of the sintered magnet 100 {see FIG. 2 (a)} faces directly below. Then, by driving the motor 36 in this state, the rotating part 34 and the sintered magnet 100 are circumferentially arranged around the rotation axis S1 (indicated by the alternate long and short dash line) extending in the arrow A direction (arrow C1 direction: see FIG. 4). Rotate to

  The grindstone unit 14 includes a base 40, an L-shaped plate-like member 42 provided on the base 40, a motor 44 attached to the plate-like member 42, a spindle unit 46 provided on the base 40, and a spindle unit 46. Including a grindstone 48 attached to the.

  The spindle unit 46 includes a spindle shaft 50 extending in the direction of arrow B, and a support portion 52 that rotatably supports the spindle shaft 50. One end of the spindle shaft 50 is connected to the motor 44. A grindstone 48 is attached to the other end of the spindle shaft 50. The grindstone 48 is formed in a cylindrical shape extending in the arrow B direction. As the grindstone 48, a base made of a cemented carbide alloy with diamond abrasive grains electrodeposited or the like is used.

  In such a grindstone unit 14, by driving the motor 44, the spindle shaft 50 and the grindstone 48 are moved in the circumferential direction (arrow C2 direction: see FIG. 4) around a rotation axis S2 (shown by a one-dot chain line) extending in the arrow B direction. ) To rotate.

  In this embodiment, the motor 36 corresponds to first rotating means, the motor 44 corresponds to second rotating means, and the robot arm 18 functions as first and second moving means. The arrangement means includes the robot arm 18, the robot hand 20, and the spindle unit 46.

Next, the main operation of the chamfering apparatus 10 will be described with reference to FIGS. 1, 3, and 4.
First, the sintered magnet 100 is acquired from the belt conveyor or the like by the holding unit 12. Then, as shown in FIG. 1, the obtained sintered magnet 100 is rotated 90 ° with respect to the rotation axis S2 of the grindstone 48 by the holding unit 12 and the rotation axis S1 is the rotation axis of the grindstone 48. It is held so as not to cross S2 (see FIG. 4). That is, in the chamfering apparatus 10, the sintered magnet 100 is rotated so that the rotation axis S 1 of the sintered magnet 100 is inclined by 90 ° with respect to the rotation axis S 2 of the grindstone 48 and the rotation axis S 1 of the sintered magnet 100 does not intersect the rotation axis S 2 of the grindstone 48. A magnet 100 and a grindstone 48 are arranged.

  Subsequently, the motor 36 is driven to rotate the robot hand 20 and thus the sintered magnet 100 in the direction of arrow C1 (see FIG. 4), and the motor 44 is driven to rotate the grindstone 48 in the direction of arrow C2 (see FIG. 4). . In the chamfering device 10, the motor 36 rotates the sintered magnet 100 and the motor 44 rotates the grindstone 48 so that the peripheral speed of the outer peripheral surface 48 a of the grindstone 48 is 40 times or more the peripheral speed of the outer peripheral edge 102 of the sintered magnet 100. Rotate.

  Then, the robot arm 18 performs a linear interpolation operation so that the sintered magnet 100 is moved (sent) in the direction of arrow A (the axial direction of the sintered magnet 100) and the grindstone 48 side (here, the lower side). As a result, as shown in FIGS. 3 and 4, the outer peripheral edge 102 of the sintered magnet 100 is in contact with the outer peripheral surface 48 a of the grindstone 48. Thereafter, the robot arm 18 performs a linear interpolation operation so that the sintered magnet 100 is reciprocated in the direction of arrow B (the axial direction of the grindstone 48) while moving the sintered magnet 100 in the direction of arrow A and toward the grindstone 48. As a result, the outer peripheral edge 102 reciprocates on the outer peripheral surface 48a while the outer peripheral edge 102 is pressed against the outer peripheral surface 48a, and the outer peripheral edge 102 is chamfered.

  Thereafter, if the sintered magnet 100 is moved by a predetermined amount (predetermined time) in the direction of arrow A and toward the grindstone 48, the chamfering of the outer peripheral edge 102 is completed, and the sintered magnet 100a having the chamfered surface 104 formed therein {FIG. ) Reference} is given to the belt conveyor or the like by the holding unit 12.

  According to such a chamfering apparatus 10, by reciprocating the sintered magnet 100 in the direction of the arrow B while moving the sintered magnet 100 in the direction of the arrow A, the outer peripheral edge 102 can be chamfered effectively using the entire outer peripheral surface 48a. The life of the wheel can be extended. Further, the sintered magnet 100 and the grindstone 48 are arranged such that the rotation axis S1 is inclined by 90 ° with respect to the rotation axis S2 and the rotation axis S1 and the rotation axis S2 do not intersect with each other. The outer peripheral edge 102 can be ground in the substantially radial direction of the sintered magnet 100 (arrow D direction: see FIG. 4) by rotating the peripheral edge 102 so as to be larger than the peripheral speed of the peripheral edge 102. As a result, a short polishing line (grinding line) extending in a direction intersecting with the arrow C1 direction (see FIG. 4) can be formed on the chamfered surface 104 {see FIG.

  By setting the peripheral speed of the outer peripheral surface 48 a to 40 times or more the peripheral speed of the outer peripheral edge 102, the outer peripheral edge 102 can be reliably ground in the direction of the arrow D (see FIG. 4), and reliably on the chamfered surface 104. A short abrasive line can be formed.

  Next, a comparative example of the sintered magnet chamfered by the chamfering device of the prior art and the sintered magnet chamfered by the chamfering device 10 will be described. In any of the chamfering apparatuses, the sintered magnet 100 having a diameter (outer diameter) of the outer peripheral edge 102 of 32 mm was chamfered.

  In the chamfering device of the prior art, the sintered magnet 100 and the cup-type grindstone are arranged coaxially, and the outer peripheral edge 102 of the sintered magnet 100 is pressed against the tapered inner peripheral surface of the cup-type grindstone. The outer peripheral edge 102 was chamfered by rotating in the direction.

  In the chamfering apparatus 10, a cylindrical grindstone 48 having an end surface 48b (see FIG. 4) with a diameter of 30 mm was used. Moreover, in the chamfering apparatus 10, the sintered magnet 100 was rotated so that the rotation speed of the outer peripheral edge 102 was 120 rpm, and the grindstone 48 was rotated so that the rotation speed of the outer peripheral surface 48a was 6000 rpm. If the peripheral speed of the outer peripheral edge 102 and the peripheral speed of the outer peripheral surface 48a are obtained from this condition using diameter × circularity × rotational speed, the peripheral speed of the outer peripheral edge 102 is about 0.2 m / s, and the outer peripheral surface 48a. The peripheral speed is about 9.4 m / s. Therefore, the peripheral speed of the outer peripheral surface 48 a is about 47 times the peripheral speed of the outer peripheral edge 102.

The principal part of the sintered magnet chamfered by the chamfering apparatus of the prior art is shown in FIG. 5, and the principal part of the sintered magnet chamfered by the chamfering apparatus 10 is shown in FIG.
In the conventional chamfering apparatus, since the outer peripheral edge is ground in the circumferential direction, a polishing mark extending in the circumferential direction is formed on the chamfered surface as shown in FIG. On the other hand, in the chamfering device 10, the inclination between the rotation shaft S <b> 1 and the rotation shaft S <b> 2 is 90 °, and the peripheral speed of the outer peripheral surface 48 a of the grindstone 48 is significantly larger than the peripheral speed of the outer peripheral edge 102 of the sintered magnet 100. The sintered magnet 100 can be ground substantially in the direction of arrow D (see FIG. 4). As a result, as shown in FIG. 6, it is possible to form polished eyes extending substantially radially on the chamfered surface.

  In general, in order to remove burrs and round corners, for example, rotating a container containing abrasive grains and a plurality of chamfered sintered magnets to barrel the chamfered sintered magnets is known. It has been.

  In the sintered magnet chamfered by the chamfering device of the prior art, since a long polishing mark extending in the circumferential direction is formed on the chamfered surface, the outer surface after chamfering is caused by colliding with another sintered magnet during barrel processing. The vicinity of the periphery (see FIG. 5) is likely to be chipped, and the range of the chip is likely to be wide along a long polishing eye. On the other hand, in the sintered magnet 100a chamfered by the chamfering device 10, since the short crevice extending substantially radially is formed on the chamfered surface 104, even if it collides with other sintered magnets 100a, the vicinity of the outer peripheral edge after chamfering ( 6), the range can be reduced.

  The sintered magnet 100a chamfered by the chamfering apparatus 10 in this way is formed with short grinding marks extending substantially radially on the chamfered surface 104, so that the chamfered surface 104 and the vicinity thereof are less likely to be chipped during barrel processing. Good properties.

  In the above-described embodiment, the case where the first and second moving units are configured by the robot arm 18 has been described. However, the first and second moving units can be arbitrarily configured. For example, the sintered magnet may be moved to the grindstone side by the first actuator as the first moving means, and the sintered magnet may be moved in the axial direction of the grindstone by the second actuator as the second moving means.

  Further, in the above-described embodiment, the case where the sintered magnet and the grindstone are arranged so as to be aligned in the vertical direction has been described. However, if the inclination between one rotating shaft and the other rotating shaft is 90 °, the sintered magnet There is no particular limitation on the arrangement of the grindstone. For example, the sintered magnet and the grindstone may be arranged such that the rotating shaft of the sintered magnet extends in the horizontal direction and the rotating shaft of the grindstone extends in the vertical direction, or the rotating shaft of the sintered magnet and the rotating shaft of the grindstone A sintered magnet and a grindstone may be arranged so that each extends in the horizontal direction.

  Furthermore, although the above-mentioned embodiment demonstrated the case where a sintered magnet was moved, this invention is not limited to this. What is necessary is just to press-contact the outer periphery of a sintered magnet to the outer peripheral surface of a grindstone by moving at least any one of a sintered magnet and a grindstone. Moreover, what is necessary is just to reciprocate the outer periphery of a sintered magnet on the outer peripheral surface of a grindstone by moving at least any one of a sintered magnet and a grindstone.

  In addition, although the above-mentioned embodiment demonstrated the case where a cylindrical sintered magnet was chamfered, this invention is not limited to this. For example, a cylindrical sintered magnet may be chamfered.

It is a side view solution figure showing one embodiment of this invention. It is a perspective view which shows a sintered magnet, (a) shows the sintered magnet before chamfering, (b) shows the sintered magnet after chamfering. It is a side view solution figure which shows the state which moved the sintered magnet to the vertical direction and the grindstone side from the state of FIG. It is a perspective view solution figure which shows the state which the outer periphery of the sintered magnet and the outer peripheral surface of the grindstone contacted. It is an illustration figure which shows the principal part of the sintered magnet chamfered by the conventional chamfering apparatus. It is an illustration figure which shows the principal part of the sintered magnet chamfered by the chamfering apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Chamfering device 12 Holding unit 14 Grinding wheel unit 18 Robot arm 20 Robot hand 30, 36, 44 Motor 46 Spindle unit 48 Grinding wheel 48a Outer peripheral surface 100, 100a Sintered magnet 102 Outer peripheral edge 104 Chamfered surface S1, S2 Rotating shaft

Claims (2)

A chamfering device for a cylindrical or columnar sintered magnet having a circular outer periphery,
Cylindrical whetstone,
First rotating means for rotating the sintered magnet in the circumferential direction;
Second rotating means for rotating the grindstone in the circumferential direction so that the peripheral speed of the outer peripheral surface of the grindstone is larger than the peripheral speed of the outer peripheral edge of the sintered magnet;
Arrangement means for arranging the sintered magnet and the grindstone so that one rotation axis is inclined by 90 ° with respect to the other rotation axis and one rotation axis does not cross the other rotation axis,
First moving means for moving at least one of the sintered magnet and the grindstone to the other side so that the outer circumferential edge of the sintered magnet is in contact with the outer circumferential surface of the grindstone, and the outer circumferential edge of the sintered magnet is A second moving means for moving at least one of the sintered magnet and the grindstone in the axial direction of the grindstone so as to reciprocate on the outer peripheral surface of the grindstone ;
The arrangement means includes a rotating portion rotated by the first rotating means and a claw that can rotate together with the rotating portion, and the outer peripheral surface of the sintered magnet is sandwiched between the claws so as to be coaxial with the rotating portion. And the chamfering apparatus which hold | maintains the said sintered magnet so that the end surface of the said sintered magnet faces right below . A chamfering method for chamfering a circular outer periphery of a cylindrical or columnar sintered magnet,
Arranging the sintered magnet and the cylindrical grindstone so that one rotation axis is inclined by 90 ° with respect to the other rotation axis and one rotation axis does not cross the other rotation axis;
Rotating the sintered magnet and the grindstone in the circumferential direction so that the peripheral speed of the outer peripheral surface of the grindstone is larger than the peripheral speed of the outer peripheral edge of the sintered magnet, and the outer peripheral edge of the sintered magnet So that the outer peripheral edge of the sintered magnet reciprocates on the outer peripheral surface of the grindstone while moving at least one of the sintered magnet and the grindstone to the other side so as to contact the outer peripheral surface of the grindstone A step of moving at least one of the sintered magnet and the grindstone in the axial direction of the grindstone ,
In the arranging step, the sintered magnet is arranged so that the outer peripheral surface of the sintered magnet is sandwiched between claws that can rotate together with the rotating portion, so that the end surface of the sintered magnet faces directly below the rotating portion. Hold
In the rotating step , the chamfering method of rotating the sintered magnet held by the claw in the circumferential direction by rotating the rotating portion in the circumferential direction .